code: def test_error_when_q_not_number():
      with pytest.raises(ValueError):
          EqualFrequencyDiscretiser(q="other")
  
file_path: feature_engine/tests/test_discretisation/test_equal_frequency_discretiser.py
imports: import pandas
  import pytest
  from sklearn.exceptions import NotFittedError
  from feature_engine.discretisation import EqualFrequencyDiscretiser
label_desc: Use image node_id 3 for calling a global function with example usage: test_error_when_q_not_number() without return types