Set<SourceName> analyzeExpression(
      final Expression expression,
      final String clauseType
  ) {
    final Validator extractor = new Validator(clauseType);
    extractor.process(expression, null);
    return extractor.referencedSources;
  }
@Test
  public void shouldNotThrowOnPossibleSyntheticKeyColumn() {
    // Given:
    when(sourceSchemas.isJoin()).thenReturn(true);

    // When:
    analyzer.analyzeExpression(POSSIBLE_SYNTHETIC_KEY, "SELECT");

    // Then: did not throw.
  }