static boolean isValidComparison(
      final SqlType left, final ComparisonExpression.Type operator, final SqlType right
  ) {
    if (left == null || right == null) {
      throw nullSchemaException(left, operator, right);
    }

    return HANDLERS.stream()
        .filter(h -> h.handles.test(left.baseType()))
        .findFirst()
        .map(h -> h.validator.test(operator, right))
        .orElse(false);
  }
@SuppressWarnings("ConstantConditions")
  @Test
  public void shouldNotCompareLeftNullSchema() {
    // When:
    final Exception e = assertThrows(
        KsqlException.class,
        () -> ComparisonUtil.isValidComparison(null, ComparisonExpression.Type.EQUAL, SqlTypes.STRING)
    );

    // Then:
    assertThat(e.getMessage(), containsString(
        "Comparison with NULL not supported: NULL = STRING"));
  }