@Override
    public void writeRecord(Tuple2 tuple2) throws IOException {
        Tuple2<Boolean, Row> tupleTrans = tuple2;
        Boolean retract = tupleTrans.getField(0);
        Row row = tupleTrans.getField(1);
        try {
            if (retract) {
                insertWrite(row);
            } else {
                //do nothing
            }
        } catch (Exception e) {
            throw new IllegalArgumentException("writeRecord() failed", e);
        }
    }
Adds a record to the prepared statement.
<p>
When this method is called, the output format is guaranteed to be opened.
</p>
<p>
WARNING: this may fail when no column types specified (because a best effort approach is attempted in order to
insert a null value but it's not guaranteed that the JDBC driver handles PreparedStatement.setObject(pos, null))

@param tuple2 The records to add to the output.
@throws IOException Thrown, if the records could not be added due to an I/O problem.
@see PreparedStatement
cassandra/cassandra-sink/src/main/java/com/dtstack/flink/sql/sink/cassandra/CassandraOutputFormat.java