code: def test_weights_zero():
      knorau_test = KNORAU()
      competences = np.zeros((1, 3))
      result = knorau_test.select(competences)
  
      assert np.all(result)
  
file_path: DESlib/deslib/tests/des/test_knorau.py
imports: import numpy
  from sklearn.linear_model import Perceptron
  from sklearn.utils.estimator_checks import check_estimator
  from deslib.des.knora_u import KNORAU
label_desc: Use image node_id 3 for calling a global function with example usage: test_weights_zero() without return types