docstr: Checks if the function works when the user doesn't define groups at
  all.
docstr_tok: ["Checks","if","the","function","works","when","the","user","does","n't","define","groups","at","all","."]
code: def test_define_problem_with_groups_no_group_definition(self):
      """
      Checks if the function works when the user doesn't define groups at
      all.
      """
      problem = {
          "num_vars": 8,
          "names": ["x1", "x2", "x3", "x4", "x5", "x6", "x7", "x8"],
      }
  
      expected = {
          "num_vars": 8,
          "names": ["x1", "x2", "x3", "x4", "x5", "x6", "x7", "x8"],
          "groups": ["x1", "x2", "x3", "x4", "x5", "x6", "x7", "x8"],
      }
  
      result = _define_problem_with_groups(problem)
  
      assert expected == result
  
imports: from numpy.testing import assert_equal, assert_allclose
  from pytest import raises, fixture, warns, mark
  import numpy
  import warnings
  from SALib.sample.morris.morris import sample, _check_group_membership, _check_if_num_levels_is_even, _compute_optimised_trajectories, _generate_p_star, _compute_b_star, _generate_trajectory, _generate_x_star
  from SALib.util import read_param_file, compute_groups_matrix, _define_problem_with_groups, _compute_delta
label_desc: Use image node_id 7 for calling the TestGroupSampleGeneration obj's underlying member method code with example usage: obj.test_define_problem_with_groups_no_group_definition() without return types