public com.google.protobuf.ByteString getClusterIdBytes() {
        java.lang.Object ref = clusterId_;
        if (ref instanceof String) {
          com.google.protobuf.ByteString b =
              com.google.protobuf.ByteString.copyFromUtf8((java.lang.String) ref);
          clusterId_ = b;
          return b;
        } else {
          return (com.google.protobuf.ByteString) ref;
        }
      }
<pre>
Required. The user-provided identifier of the new `Cluster`.
The identifier must meet the following requirements:

* Only contains 1-63 alphanumeric characters and hyphens
* Begins with an alphabetical character
* Ends with a non-hyphen character
* Not formatted as a UUID
* Complies with [RFC
1034](https://datatracker.ietf.org/doc/html/rfc1034) (section 3.5)
</pre>

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

@return The bytes for clusterId.
java-vmwareengine/proto-google-cloud-vmwareengine-v1/src/main/java/com/google/cloud/vmwareengine/v1/PrivateCloud.java