public List<String> getAllColumns() {
    List<String> columns = new ArrayList<>();
    if (_columnNamesArray == null) {
      return columns;
    }

    for (JsonNode column : _columnNamesArray) {
      columns.add(column.textValue());
    }

    return columns;
  }
@Test
  public void testGetAllColumns() {
    // Run the test
    final List<String> result = _resultTableResultSetUnderTest.getAllColumns();

    // Verify the results
    assertNotNull(result);
    assertEquals(2, result.size());
  }