public Builder mergeReadMask(com.google.protobuf.FieldMask value) {
      if (readMaskBuilder_ == null) {
        if (((bitField0_ & 0x00000010) != 0)
            && readMask_ != null
            && readMask_ != com.google.protobuf.FieldMask.getDefaultInstance()) {
          getReadMaskBuilder().mergeFrom(value);
        } else {
          readMask_ = value;
        }
      } else {
        readMaskBuilder_.mergeFrom(value);
      }
      if (readMask_ != null) {
        bitField0_ |= 0x00000010;
        onChanged();
      }
      return this;
    }
<pre>
Optional. Mask specifying which fields to read.
</pre>

<code>.google.protobuf.FieldMask read_mask = 5 [(.google.api.field_behavior) = OPTIONAL];
</code>
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/ListEndpointsRequest.java