public void addToColumns(TColumnValue elem) {
    if (this.columns == null) {
      this.columns = new java.util.ArrayList<TColumnValue>();
    }
    this.columns.add(elem);
  }
Returns true if field row is set (has been assigned a value) and false otherwise
hbase-thrift/src/main/java/org/apache/hadoop/hbase/thrift2/generated/TAppend.java