below is a section of a #docker compose file. Why is it that under environment in share you have different sections such as JAVA_OPTS, but under solr6 the configs just have a - in front of them. I tried adding JAVA_OPTS to solr6 and got a yml syntax error

```
share:
image: alfresco/alfresco-share:6.2.0
mem_limit: 1g
environment:
REPO_HOST: "alfresco"
REPO_PORT: "8080"
JAVA_OPTS: "
-Xms500m
-Xmx500m
-Dalfresco.host=localhost
-Dalfresco.port=8080
-Dalfresco.context=alfresco
-Dalfresco.protocol=http
"

solr6:
image: alfresco/alfresco-search-services:1.4.2.1
mem_limit: 4g
environment:
#JAVA_OPTS: "-Dsolr.log.level=FINE"
#Solr needs to know how to register itself with Alfresco
- SOLR_ALFRESCO_HOST=alfresco
- SOLR_ALFRESCO_PORT=8080
#Alfresco needs to know how to call solr
- SOLR_SOLR_HOST=solr6
- SOLR_SOLR_PORT=8983
#Create the default alfresco and archive cores
- SOLR_CREATE_ALFRESCO_DEFAULTS=alfresco,archive
#HTTP by default
- ALFRESCO_SECURE_COMMS=none
```