@Override
      public void write(org.apache.thrift.protocol.TProtocol prot, modifyNamespace_result struct) throws org.apache.thrift.TException {
        org.apache.thrift.protocol.TTupleProtocol oprot = (org.apache.thrift.protocol.TTupleProtocol) prot;
        java.util.BitSet optionals = new java.util.BitSet();
        if (struct.isSetIo()) {
          optionals.set(0);
        }
        oprot.writeBitSet(optionals, 1);
        if (struct.isSetIo()) {
          struct.io.write(oprot);
        }
      }
Returns true if field corresponding to fieldID is set (has been assigned a value) and false otherwise
hbase-thrift/src/main/java/org/apache/hadoop/hbase/thrift2/generated/THBaseService.java