public com.google.protobuf.ByteString getCustomTimeBytes() {
      java.lang.Object ref = customTime_;
      if (ref instanceof String) {
        com.google.protobuf.ByteString b =
            com.google.protobuf.ByteString.copyFromUtf8((java.lang.String) ref);
        customTime_ = b;
        return b;
      } else {
        return (com.google.protobuf.ByteString) ref;
      }
    }
<pre>
Optional. Updates objects Custom-Time fixed metadata. Unset values will be
ignored. Set empty values to clear the metadata. Refer to documentation in
https://cloud.google.com/storage/docs/metadata#custom-time.
</pre>

<code>optional string custom_time = 6 [(.google.api.field_behavior) = OPTIONAL];</code>

@return The bytes for customTime.
java-storagebatchoperations/proto-google-cloud-storagebatchoperations-v1/src/main/java/com/google/cloud/storagebatchoperations/v1/PutMetadata.java