code: def test_wrong_length(self):
      with self.assertRaises(ValueError):
          cvec(-1)
  
imports: import numpy
  from numpy.testing import TestCase, assert_equal
  from aubio import cvec, fvec, float_type
label_desc: Use image node_id 1 for calling the aubio_cvec_wrong_norm_input obj's underlying member method code with example usage: obj.test_wrong_length() without return types