public com.google.protobuf.ByteString getProjectIdBytes() {
        java.lang.Object ref = projectId_;
        if (ref instanceof String) {
          com.google.protobuf.ByteString b =
              com.google.protobuf.ByteString.copyFromUtf8((java.lang.String) ref);
          projectId_ = b;
          return b;
        } else {
          return (com.google.protobuf.ByteString) ref;
        }
      }
<pre>
Required. The ID of the Google Cloud project that owns the job.
</pre>

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

@return The bytes for projectId.
java-storage-transfer/proto-google-cloud-storage-transfer-v1/src/main/java/com/google/storagetransfer/v1/proto/TransferProto.java