public static ColumnName generateSyntheticJoinKey(final Stream<LogicalSchema> schemas) {
    final AliasGenerator generator = buildAliasGenerators(schemas)
        .getOrDefault(
            SYNTHETIC_JOIN_KEY_COLUMN_PRIFIX,
            new AliasGenerator(0, SYNTHETIC_JOIN_KEY_COLUMN_PRIFIX, ImmutableSet.of())
        );

    return generator.next();
  }
@Test
  public void shouldDefaultToRowKeySyntheticJoinColumn() {
    // When:
    final ColumnName columnName = ColumnNames.generateSyntheticJoinKey(Stream.of());

    // Then:
    assertThat(columnName, is(ColumnName.of("ROWKEY")));
  }