GeneratedMessage.java 文件源码

/** Get the OneofAccessor for a particular oneof. */
private OneofAccessor getOneof(final OneofDescriptor oneof) {
  if (oneof.getContainingType() != descriptor) {
    throw new IllegalArgumentException(
      "OneofDescriptor does not match message type.");
  }
  return oneofs[oneof.getIndex()];
}