code: def testZero(self):
      # zeros should return no onsets (empty array)
      n = 10
      detection = zeros(100).reshape(n, n)
      weights = ones(n)
      self.assertEqualMatrix(Onsets()(detection, weights), [])
  
file_path: essentia/test/src/unittests/rhythm/test_onsets.py
imports: from essentia_test import *
label_desc: Use image node_id 1 for calling the TestOnsets obj's underlying member method code with example usage: obj.testZero() without return types