def METHOD_NAME(two_reservoir_constrained_problem):
    """Test the initialisation of a constrained platypus problem."""
    p = two_reservoir_constrained_problem
    assert p.problem.nvars == 12
    assert p.problem.nobjs == 2
    assert p.problem.nconstrs == 2
    # Check the `customise_model` method has been called.
    assert p.the_model_has_been_customised