@java.lang.Override
      public java.lang.String getChannelId() {
        java.lang.Object ref = channelId_;
        if (ref instanceof java.lang.String) {
          return (java.lang.String) ref;
        } else {
          com.google.protobuf.ByteString bs = (com.google.protobuf.ByteString) ref;
          java.lang.String s = bs.toStringUtf8();
          channelId_ = s;
          return s;
        }
      }
<pre>
Required. The Slack channel ID.
</pre>

<code>string channel_id = 1 [(.google.api.field_behavior) = REQUIRED];</code>

@return The channelId.
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/SlackSource.java