public Builder addExtensionRange(
          com.google.protobuf.DescriptorProtos.DescriptorProto.ExtensionRange.Builder builderForValue) {
        if (extensionRangeBuilder_ == null) {
          ensureExtensionRangeIsMutable();
          extensionRange_.add(builderForValue.build());
          onChanged();
        } else {
          extensionRangeBuilder_.addMessage(builderForValue.build());
        }
        return this;
      }