presto-example-http/src/main/java/io/prestosql/plugin/example/ExampleRecordSetProvider.java/ExampleRecordSetProvider/getRecordSet
class ExampleRecordSetProvider:    @Override
    public RecordSet getRecordSet(ConnectorTransactionHandle transaction, ConnectorSession session, ConnectorSplit split, ConnectorTableHandle table, List<? extends ColumnHandle> columns)
    {
        ExampleSplit exampleSplit = (ExampleSplit) split;

        ImmutableList.Builder<ExampleColumnHandle> handles = ImmutableList.builder();
        for (ColumnHandle handle : columns) {
            handles.add((ExampleColumnHandle) handle);
        }

        return new ExampleRecordSet(exampleSplit, handles.build());
    }