From c240fe32adb9cdff2471bee32dd58357d36c22e0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Wolfgang=20Hu=C3=9F?= <wolle.huss@pjannto.com>
Date: Fri, 1 Dec 2023 14:38:42 +0100
Subject: [PATCH 1/9] Add more detailed logs for the scripts

- Ignore 'backup-cron-job.log' files.
---
 .gitignore                                | 1 +
 deployment/scripts/cluster.backup.sh      | 3 +++
 deployment/scripts/cluster.maintenance.sh | 2 ++
 deployment/scripts/cluster.neo4j.sh       | 4 ++++
 4 files changed, 10 insertions(+)

diff --git a/.gitignore b/.gitignore
index 928dae262..a0a08dcaa 100644
--- a/.gitignore
+++ b/.gitignore
@@ -8,6 +8,7 @@ yarn-error.log*
 .yarn-integrity
 .eslintcache
 kubeconfig.yaml
+backup-cron-job.log
 
 node_modules/
 cypress/videos
diff --git a/deployment/scripts/cluster.backup.sh b/deployment/scripts/cluster.backup.sh
index 93c29dd92..7da493e4b 100755
--- a/deployment/scripts/cluster.backup.sh
+++ b/deployment/scripts/cluster.backup.sh
@@ -27,13 +27,16 @@ mkdir -p ${BACKUP_FOLDER}
 ${SCRIPT_DIR}/cluster.neo4j.sh maintenance on
 
 # database backup
+echo "Dumping database ..."
 kubectl --kubeconfig=${KUBECONFIG} -n default exec -it \
     $(kubectl --kubeconfig=${KUBECONFIG} -n default get pods | grep ocelot-neo4j | awk '{ print $1 }') \
     -- neo4j-admin dump --database=neo4j --to=/var/lib/neo4j/$BACKUP_DATE-neo4j-dump
 # copy neo4j backup to local drive
+echo "Coping database ..."
 kubectl --kubeconfig=${KUBECONFIG} cp \
     default/$(kubectl --kubeconfig=${KUBECONFIG} -n default get pods | grep ocelot-neo4j |awk '{ print $1 }'):/var/lib/neo4j/$BACKUP_DATE-neo4j-dump $BACKUP_FOLDER/neo4j-dump
 # copy image data
+echo "Coping public uploads ..."
 kubectl --kubeconfig=${KUBECONFIG} cp \
     default/$(kubectl --kubeconfig=${KUBECONFIG} -n default get pods | grep ocelot-backend |awk '{ print $1 }'):/app/public/uploads $BACKUP_FOLDER/public-uploads
 
diff --git a/deployment/scripts/cluster.maintenance.sh b/deployment/scripts/cluster.maintenance.sh
index b64994e9b..33c52254d 100755
--- a/deployment/scripts/cluster.maintenance.sh
+++ b/deployment/scripts/cluster.maintenance.sh
@@ -16,9 +16,11 @@ KUBECONFIG=${KUBECONFIG:-${SCRIPT_DIR}/../configurations/${CONFIGURATION}/kubeco
 
 case $1 in
     on)
+        echo "Network maintenance:  on"
         kubectl --kubeconfig=${KUBECONFIG} patch ingress ingress-ocelot-webapp --type merge --patch-file ${SCRIPT_DIR}/../src/kubernetes/patches/patch.ingress.maintenance.on.yaml
     ;;
     off)
+        echo "Network maintenance:  off"
         kubectl --kubeconfig=${KUBECONFIG} patch ingress ingress-ocelot-webapp --type merge --patch-file ${SCRIPT_DIR}/../src/kubernetes/patches/patch.ingress.maintenance.off.yaml
     ;;
     *)
diff --git a/deployment/scripts/cluster.neo4j.sh b/deployment/scripts/cluster.neo4j.sh
index 41ebe4227..ae539b314 100755
--- a/deployment/scripts/cluster.neo4j.sh
+++ b/deployment/scripts/cluster.neo4j.sh
@@ -21,20 +21,24 @@ case $1 in
                 ${SCRIPT_DIR}/cluster.maintenance.sh on
 
                 # set Neo4j in offline mode (maintenance)
+                echo "Neo4j maintenance:  on"
                 kubectl --kubeconfig=${KUBECONFIG} get deployment ocelot-neo4j -o json \
                     | jq '.spec.template.spec.containers[] += {"command": ["tail", "-f", "/dev/null"]}' \
                     | kubectl --kubeconfig=${KUBECONFIG} apply -f -
 
                 # wait for the container to restart
+                echo "Wait 60s ..."
                 sleep 60
             ;;
             off)
                 # set Neo4j in online mode
+                echo "Neo4j maintenance:  off"
                 kubectl --kubeconfig=${KUBECONFIG} get deployment ocelot-neo4j -o json \
                     | jq 'del(.spec.template.spec.containers[].command)' \
                     | kubectl --kubeconfig=${KUBECONFIG} apply -f -
 
                 # wait for the container to restart
+                echo "Wait 60s ..."
                 sleep 60
 
                 # maintenance mode off

From 4351c9e0dba77f7a73949a7ea17d038f34ba53b3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Wolfgang=20Hu=C3=9F?= <wolle.huss@pjannto.com>
Date: Fri, 1 Dec 2023 14:40:26 +0100
Subject: [PATCH 2/9] Refine script readme

---
 deployment/deployment.md | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/deployment/deployment.md b/deployment/deployment.md
index ebcc2f6ca..88b4f39de 100644
--- a/deployment/deployment.md
+++ b/deployment/deployment.md
@@ -109,7 +109,7 @@ The backups will be saved into your networks folders `backup` folder in a new fo
 
 ⚠️ *Attention: Please check carefully whether really the oldest backups have been deleted. As shells on different systems behave differently with regard to the commands used in this script.*
 
-Install automated backups by a cron job.
+Install automated backups by a [cron job](https://en.wikipedia.org/wiki/Cron).
 Be aware of having the bash shell installed to run the script.
 The environment variables for the automated backups are described above.
 
@@ -131,3 +131,7 @@ In the editor add the line:
 ```
 
 This way the terminal output is written into a log file named `backup-cron-job.log` located in the deployment folder.
+
+Be aware that the server datetime can differ from your local time.
+Especially by the change between summer and winter time, because servers usually have UTC.
+Find out the actual difference by running the command `date` on your server.

From 7d4a75a94c31b00c1af40cd271c3e82b5293341c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Wolfgang=20Hu=C3=9F?= <wolle.huss@pjannto.com>
Date: Fri, 1 Dec 2023 15:02:25 +0100
Subject: [PATCH 3/9] Refine checking of definition of variables

---
 deployment/scripts/cluster.backup.sh                   | 2 +-
 deployment/scripts/cluster.maintenance.sh              | 2 +-
 deployment/scripts/cluster.neo4j.sh                    | 2 +-
 deployment/scripts/clusters.backup-multiple-servers.sh | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/deployment/scripts/cluster.backup.sh b/deployment/scripts/cluster.backup.sh
index 7da493e4b..2d3bf156e 100755
--- a/deployment/scripts/cluster.backup.sh
+++ b/deployment/scripts/cluster.backup.sh
@@ -9,7 +9,7 @@ SCRIPT_PATH=$(realpath $0)
 SCRIPT_DIR=$(dirname $SCRIPT_PATH)
 
 # check CONFIGURATION
-if [[ -z ${CONFIGURATION} ]]; then
+if [[ -z "$CONFIGURATION" ]] || [[ $CONFIGURATION == "" ]]; then
   echo "!!! You must provide a CONFIGURATION via environment variable !!!"
   exit 1
 fi
diff --git a/deployment/scripts/cluster.maintenance.sh b/deployment/scripts/cluster.maintenance.sh
index 33c52254d..780b81bd6 100755
--- a/deployment/scripts/cluster.maintenance.sh
+++ b/deployment/scripts/cluster.maintenance.sh
@@ -5,7 +5,7 @@ SCRIPT_PATH=$(realpath $0)
 SCRIPT_DIR=$(dirname $SCRIPT_PATH)
 
 # check CONFIGURATION
-if [ -z ${CONFIGURATION} ]; then
+if [[ -z "$CONFIGURATION" ]] || [[ $CONFIGURATION == "" ]]; then
   echo "You must provide a `CONFIGURATION` via environment variable"
   exit 1
 fi
diff --git a/deployment/scripts/cluster.neo4j.sh b/deployment/scripts/cluster.neo4j.sh
index ae539b314..3b284c0b7 100755
--- a/deployment/scripts/cluster.neo4j.sh
+++ b/deployment/scripts/cluster.neo4j.sh
@@ -5,7 +5,7 @@ SCRIPT_PATH=$(realpath $0)
 SCRIPT_DIR=$(dirname $SCRIPT_PATH)
 
 # check CONFIGURATION
-if [ -z ${CONFIGURATION} ]; then
+if [[ -z "$CONFIGURATION" ]] || [[ $CONFIGURATION == "" ]]; then
   echo "You must provide a `CONFIGURATION` via environment variable"
   exit 1
 fi
diff --git a/deployment/scripts/clusters.backup-multiple-servers.sh b/deployment/scripts/clusters.backup-multiple-servers.sh
index 3dfcb1d79..e81165457 100755
--- a/deployment/scripts/clusters.backup-multiple-servers.sh
+++ b/deployment/scripts/clusters.backup-multiple-servers.sh
@@ -17,7 +17,7 @@ source ${SCRIPT_DIR}/../.env
 set +a
 
 # check BACKUP_CONFIGURATIONS
-if [[ -z ${BACKUP_CONFIGURATIONS} ]]; then
+if [[ -z "$BACKUP_CONFIGURATIONS" ]] || [[ $BACKUP_CONFIGURATIONS == "" ]]; then
   #%! echo "You must provide a BACKUP_CONFIGURATIONS via environment variable"
   printf "!!! You must provide a BACKUP_CONFIGURATIONS via environment variable !!!\n"
   exit 1

From 1dc871d3069917d9e4720f093aa320368012aa58 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Wolfgang=20Hu=C3=9F?= <wolle.huss@pjannto.com>
Date: Fri, 1 Dec 2023 15:06:38 +0100
Subject: [PATCH 4/9] Add database name as variable to script

---
 deployment/scripts/cluster.backup.sh | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/deployment/scripts/cluster.backup.sh b/deployment/scripts/cluster.backup.sh
index 2d3bf156e..88fdb7c6d 100755
--- a/deployment/scripts/cluster.backup.sh
+++ b/deployment/scripts/cluster.backup.sh
@@ -14,6 +14,13 @@ if [[ -z "$CONFIGURATION" ]] || [[ $CONFIGURATION == "" ]]; then
   exit 1
 fi
 
+# check DATABASE_NAME or set default
+if [[ -z "$DATABASE_NAME" ]] || [[ $DATABASE_NAME == "" ]]; then
+  DATABASE_NAME="neo4j"
+  printf "Set satabase default name.\n"
+fi
+printf "Database name:  '%s'\n" $DATABASE_NAME
+
 # configuration
 KUBECONFIG=${KUBECONFIG:-${SCRIPT_DIR}/../configurations/${CONFIGURATION}/kubeconfig.yaml}
 BACKUP_DATE=$(date "+%F_%H-%M-%S")
@@ -30,7 +37,7 @@ ${SCRIPT_DIR}/cluster.neo4j.sh maintenance on
 echo "Dumping database ..."
 kubectl --kubeconfig=${KUBECONFIG} -n default exec -it \
     $(kubectl --kubeconfig=${KUBECONFIG} -n default get pods | grep ocelot-neo4j | awk '{ print $1 }') \
-    -- neo4j-admin dump --database=neo4j --to=/var/lib/neo4j/$BACKUP_DATE-neo4j-dump
+    -- neo4j-admin dump --database=$DATABASE_NAME --to=/var/lib/neo4j/$BACKUP_DATE-neo4j-dump
 # copy neo4j backup to local drive
 echo "Coping database ..."
 kubectl --kubeconfig=${KUBECONFIG} cp \

From 64ac68bd01b687ce83dabc6a8390793e21e40cc7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Wolfgang=20Hu=C3=9F?= <wolle.huss@pjannto.com>
Date: Tue, 12 Dec 2023 15:43:47 +0100
Subject: [PATCH 5/9] Add 'NEO4J_dbms_default__database' to
 'docker-compose.yml' as commented example

---
 docker-compose.yml | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/docker-compose.yml b/docker-compose.yml
index 78cee69b3..7954e2bab 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -111,10 +111,12 @@ services:
       # settings reference: https://neo4j.com/docs/operations-manual/4.4/docker/ref-settings/
       # TODO: This sounds scary for a production environment
       - NEO4J_AUTH=none
+      # - NEO4J_dbms_default__database=graph.db
+      # - NEO4J_dbms_default__database=neo4j
       - NEO4J_dbms_security_procedures_unrestricted=algo.*,apoc.*
       - NEO4J_dbms_allow__format__migration=true
       - NEO4J_dbms_allow__upgrade=true
-      # Uncomment following line for Neo4j Enterprise version instead of Community version
+      # uncomment following line for Neo4j Enterprise version instead of Community version
       # TODO: clarify if that is the only thing needed to unlock the Enterprise version
       # - NEO4J_ACCEPT_LICENSE_AGREEMENT=yes
       # TODO: Remove the playground from production

From e4fabc47a0e54b1b65e1b90fc0df5ad951c4d67d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Wolfgang=20Hu=C3=9F?= <wolle.huss@pjannto.com>
Date: Tue, 12 Dec 2023 15:46:24 +0100
Subject: [PATCH 6/9] Add 'Database Management Commands' to Neo4j readme

- Fix of some headings and designations.
---
 neo4j/README.md | 29 +++++++++++++++++++++++------
 1 file changed, 23 insertions(+), 6 deletions(-)

diff --git a/neo4j/README.md b/neo4j/README.md
index 9b8a460ec..d9e510d8f 100644
--- a/neo4j/README.md
+++ b/neo4j/README.md
@@ -1,4 +1,4 @@
-# Neo4J
+# Neo4j 4.4
 
 Human Connection is a social network. Using a graph based database which can
 model nodes and edges natively - a network - feels like an obvious choice. We
@@ -16,8 +16,7 @@ docker-compose up
 ```
 
 You can access Neo4J through [http://localhost:7474/](http://localhost:7474/)
-for an interactive cypher shell and a visualization of the graph.
-
+for an interactive Cypher shell and a visualization of the graph.
 
 ## Installation Without Docker
 
@@ -51,7 +50,7 @@ in `backend/.env`.
 
 Start Neo4J and confirm the database is running at [http://localhost:7474](http://localhost:7474).
 
-## Operations on Neo4j
+## Operations on Neo4j 4.4
 
 ### Docker or Docker Compose
 
@@ -143,7 +142,7 @@ $ kubectl -n default exec -it $(kubectl -n default get pods | grep ocelot-backen
 ***Cypher commands to show indexes and constraints***
 
 ```bash
-# in browser command line or cypher shell
+# in browser command line or Cypher shell
 
 # show all indexes and constraints
 $ :schema
@@ -158,7 +157,7 @@ $ CALL db.constraints();
 ***Cypher commands to create and drop indexes and constraints***
 
 ```bash
-# in browser command line or cypher shell
+# in browser command line or Cypher shell
 
 # create indexes
 $ CALL db.index.fulltext.createNodeIndex("post_fulltext_search",["Post"],["title", "content"]);
@@ -171,3 +170,21 @@ $ DROP CONSTRAINT ON ( image:Image ) ASSERT image.url IS UNIQUE
 # drop all indexes and constraints
 $ CALL apoc.schema.assert({},{},true) YIELD label, key RETURN * ;
 ```
+
+### Database Management Commands
+
+***Cypher commands to manage databases***
+
+```bash
+# in browser command line or Cypher shell
+
+# show the default database
+$ SHOW DEFAULT DATABASE
+# show all databases
+$ SHOW DATABASES
+```
+
+To set the default database by configuration, use `NEO4J_dbms_default__database` as an environment variable when starting Neo4j 4.4, see [Docker specific configuration settings](<https://neo4j.com/docs/operations-manual/4.4/docker/ref-settings/>).
+
+If a database with this name does not exist, an empty database with this name is created and all other databases remain.
+You can switch back to an existing database without damaging it.

From c931c27a106a78952b8f3e7d46c94a3f8e2d27a7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Wolfgang=20Hu=C3=9F?= <wolle.huss@pjannto.com>
Date: Tue, 12 Dec 2023 15:52:34 +0100
Subject: [PATCH 7/9] Add description option '--database=<name>' to dumping or
 loading database

---
 neo4j/README.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/neo4j/README.md b/neo4j/README.md
index d9e510d8f..f5be62eb8 100644
--- a/neo4j/README.md
+++ b/neo4j/README.md
@@ -74,6 +74,8 @@ neo4j% exit
 $ docker cp <docker-image-name('neo4j')>:/var/lib/neo4j/neo4j-dump <local-folder-path>/$(date +%F)-neo4j-dump
 ```
 
+If you need a specific database name, add the option `--database=<name>` to the command `neo4j-admin dump`.
+
 ### Import Neo4j Dump
 
 To import a dump into Neo4j running in a Docker container:
@@ -92,6 +94,8 @@ neo4j% neo4j-admin load --expand-commands --database=neo4j --from /var/lib/neo4j
 neo4j% exit
 ```
 
+If you need a specific database name, add the option `--database=<name>` to the command `neo4j-admin load`.
+
 ## Commands
 
 Here we describe some rarely used Cypher commands for Neo4j that are needed from time to time:

From af1de3d4a27450cae35f7bc9a3d99213879a9cf7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Wolfgang=20Hu=C3=9F?= <wolle.huss@pjannto.com>
Date: Tue, 12 Dec 2023 15:53:54 +0100
Subject: [PATCH 8/9] Revert "Add database name as variable to script"

This reverts commit 1dc871d3069917d9e4720f093aa320368012aa58.
---
 deployment/scripts/cluster.backup.sh | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/deployment/scripts/cluster.backup.sh b/deployment/scripts/cluster.backup.sh
index 88fdb7c6d..2d3bf156e 100755
--- a/deployment/scripts/cluster.backup.sh
+++ b/deployment/scripts/cluster.backup.sh
@@ -14,13 +14,6 @@ if [[ -z "$CONFIGURATION" ]] || [[ $CONFIGURATION == "" ]]; then
   exit 1
 fi
 
-# check DATABASE_NAME or set default
-if [[ -z "$DATABASE_NAME" ]] || [[ $DATABASE_NAME == "" ]]; then
-  DATABASE_NAME="neo4j"
-  printf "Set satabase default name.\n"
-fi
-printf "Database name:  '%s'\n" $DATABASE_NAME
-
 # configuration
 KUBECONFIG=${KUBECONFIG:-${SCRIPT_DIR}/../configurations/${CONFIGURATION}/kubeconfig.yaml}
 BACKUP_DATE=$(date "+%F_%H-%M-%S")
@@ -37,7 +30,7 @@ ${SCRIPT_DIR}/cluster.neo4j.sh maintenance on
 echo "Dumping database ..."
 kubectl --kubeconfig=${KUBECONFIG} -n default exec -it \
     $(kubectl --kubeconfig=${KUBECONFIG} -n default get pods | grep ocelot-neo4j | awk '{ print $1 }') \
-    -- neo4j-admin dump --database=$DATABASE_NAME --to=/var/lib/neo4j/$BACKUP_DATE-neo4j-dump
+    -- neo4j-admin dump --database=neo4j --to=/var/lib/neo4j/$BACKUP_DATE-neo4j-dump
 # copy neo4j backup to local drive
 echo "Coping database ..."
 kubectl --kubeconfig=${KUBECONFIG} cp \

From 0b8407ccff5d90ec0cfe7d450ebba683bfe15674 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Wolfgang=20Hu=C3=9F?= <wolle.huss@pjannto.com>
Date: Tue, 12 Dec 2023 16:13:46 +0100
Subject: [PATCH 9/9] Remove '--database=neo4j' and '--expand-commands' from
 all the database commands

---
 deployment/scripts/cluster.backup.sh | 2 +-
 deployment/src/kubernetes/Backup.md  | 4 +++-
 neo4j/README.md                      | 4 ++--
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/deployment/scripts/cluster.backup.sh b/deployment/scripts/cluster.backup.sh
index 2d3bf156e..784bb1844 100755
--- a/deployment/scripts/cluster.backup.sh
+++ b/deployment/scripts/cluster.backup.sh
@@ -30,7 +30,7 @@ ${SCRIPT_DIR}/cluster.neo4j.sh maintenance on
 echo "Dumping database ..."
 kubectl --kubeconfig=${KUBECONFIG} -n default exec -it \
     $(kubectl --kubeconfig=${KUBECONFIG} -n default get pods | grep ocelot-neo4j | awk '{ print $1 }') \
-    -- neo4j-admin dump --database=neo4j --to=/var/lib/neo4j/$BACKUP_DATE-neo4j-dump
+    -- neo4j-admin dump --to=/var/lib/neo4j/$BACKUP_DATE-neo4j-dump
 # copy neo4j backup to local drive
 echo "Coping database ..."
 kubectl --kubeconfig=${KUBECONFIG} cp \
diff --git a/deployment/src/kubernetes/Backup.md b/deployment/src/kubernetes/Backup.md
index 9f41ee7f4..bfae50776 100644
--- a/deployment/src/kubernetes/Backup.md
+++ b/deployment/src/kubernetes/Backup.md
@@ -137,7 +137,7 @@ $ kubectl -n default exec -it $(kubectl -n default get pods | grep ocelot-neo4j
 # bash: enter bash of Neo4j
 $ kubectl -n default exec -it $(kubectl -n default get pods | grep ocelot-neo4j | awk '{ print $1 }') -- bash
 # generate Dump
-neo4j% neo4j-admin dump --database=neo4j --to=/var/lib/neo4j/$(date +%F)-neo4j-dump
+neo4j% neo4j-admin dump --to=/var/lib/neo4j/$(date +%F)-neo4j-dump
 # exit bash
 neo4j% exit
 
@@ -145,6 +145,8 @@ neo4j% exit
 $ kubectl -n default exec -it $(kubectl -n default get pods | grep ocelot-neo4j | awk '{ print $1 }') -- ls
 ```
 
+If you need a specific database name, add the option `--database=<name>` to the command `neo4j-admin dump`.
+
 Lets copy the dump backup
 
 ```bash
diff --git a/neo4j/README.md b/neo4j/README.md
index f5be62eb8..fa2773d6c 100644
--- a/neo4j/README.md
+++ b/neo4j/README.md
@@ -67,7 +67,7 @@ To create a dump in Neo4j running in a Docker container:
 # connect to the Docker containers Neo4j terminal
 $ docker exec -it neo4j bash
 # generate Dump
-neo4j% neo4j-admin dump --database=neo4j --to=/var/lib/neo4j/$(date +%F)-neo4j-dump
+neo4j% neo4j-admin dump --to=/var/lib/neo4j/$(date +%F)-neo4j-dump
 # exit bash
 neo4j% exit
 # copy the dump out of the running Docker container
@@ -89,7 +89,7 @@ $ docker cp <local-folder-path>/neo4j-dump <docker-image-name('neo4j')>:/var/lib
 # connect to the Docker containers Neo4j terminal
 $ docker exec -it neo4j bash
 # to load the dump into the database we need the following command in this terminal
-neo4j% neo4j-admin load --expand-commands --database=neo4j --from /var/lib/neo4j/$(date +%F)-neo4j-dump --force
+neo4j% neo4j-admin load --from /var/lib/neo4j/$(date +%F)-neo4j-dump --force
 # leave the terminal by entering
 neo4j% exit
 ```