private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.workstations.v1beta.WorkstationConfig.Container,
            com.google.cloud.workstations.v1beta.WorkstationConfig.Container.Builder,
            com.google.cloud.workstations.v1beta.WorkstationConfig.ContainerOrBuilder>
        getContainerFieldBuilder() {
      if (containerBuilder_ == null) {
        containerBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.workstations.v1beta.WorkstationConfig.Container,
                com.google.cloud.workstations.v1beta.WorkstationConfig.Container.Builder,
                com.google.cloud.workstations.v1beta.WorkstationConfig.ContainerOrBuilder>(
                getContainer(), getParentForChildren(), isClean());
        container_ = null;
      }
      return containerBuilder_;
    }
<pre>
Optional. Container that runs upon startup for each workstation using this
workstation configuration.
</pre>

<code>
.google.cloud.workstations.v1beta.WorkstationConfig.Container container = 14 [(.google.api.field_behavior) = OPTIONAL];
</code>
java-workstations/proto-google-cloud-workstations-v1beta/src/main/java/com/google/cloud/workstations/v1beta/WorkstationConfig.java