@Override
  public LogicalSchema getSchema() {
    return schema;
  }
@Test
  public void shouldReturnCorrectSchema() {
    // When:
    final JoinNode joinNode =
        new JoinNode(nodeId, LEFT, joinKey,          true, left, right,
            WITHIN_EXPRESSION, "KAFKA");

    // Then:
    assertThat(joinNode.getSchema(), is(LogicalSchema.builder()
        .keyColumn(SYNTH_KEY, SqlTypes.BIGINT)
        .valueColumns(LEFT_NODE_SCHEMA.value())
        .valueColumns(RIGHT_NODE_SCHEMA.value())
        .valueColumn(SYNTH_KEY, SqlTypes.BIGINT)
        .build()));
  }