public TColumnValue setQualifier(byte[] qualifier) {
    this.qualifier = qualifier == null ? (java.nio.ByteBuffer)null   : java.nio.ByteBuffer.wrap(qualifier.clone());
    return this;
  }
Returns true if field family is set (has been assigned a value) and false otherwise
hbase-thrift/src/main/java/org/apache/hadoop/hbase/thrift2/generated/TColumnValue.java