new_contents: """
  Note: this test file was heavily influenced by its dbplyr counterpart.
  
  https://github.com/tidyverse/dbplyr/blob/master/tests/testthat/test-verb-select.R
  """
      
  from siuba import _, mutate, select, group_by
  
  import pytest
  from .helpers import assert_equal_query, data_frame, backend_notimpl
  from string import ascii_lowercase 
  
  DATA = data_frame(a = 1, b = 2, c = 3, d = 4, e = 5)
  
  @pytest.fixture(scope = "module")
  def dfs(backend):
      return backend.load_df(DATA)
  
  @pytest.mark.parametrize("query, output", [
      ( select(_.c), data_frame(c = 3) ),
      ( select(_.b == _.c), data_frame(b = 3) ),
      ( select(_["a":"c"]), data_frame(a = 1, b = 2, c = 3) ),
      ( select(_[_.a:_.c]), data_frame(a = 1, b = 2, c = 3) ),
      ( select(_.a, _.b) >> select(_.b), data_frame(b = 2) ),
      ( mutate(a = _.b + _.c) >> select(_.a), data_frame(a = 5) ),
      pytest.param( group_by(_.a) >> select(_.b), data_frame(b = 2, a = 1), marks = pytest.mark.xfail),
      ])
  def test_select_siu(dfs, query, output):
      assert_equal_query(dfs, query, output)
  
  
  
subject: add sql select verb tests