code: def test_fillpositive_simulated_error(dtype):
      # Nondeterministic test for fillpositive threshold
      # Create random vectors, normalize to unit length, and count on floating point
      # error to result in magnitudes larger/smaller than one
      # This is to simulate cases where a unit quaternion with w == 0 would be encoded
      # as xyz with small error, and we want to recover the w of 0
  
      # Permit 1 epsilon per value (default, but make explicit here)
      w2_thresh = 3 * np.finfo(dtype).eps
  
      pos_error = neg_error = False
      for _ in range(50):
          xyz = norm(gen_vec(dtype))
  
          assert nq.fillpositive(xyz, w2_thresh)[0] == 0.0
  
imports: import numpy
  import pytest
  from numpy import pi
  from numpy.testing import assert_array_almost_equal, assert_array_equal
  from ..None import eulerangles
  from ..None import quaternions
label_desc: Use image node_id 5 for calling a global function with example usage: test_fillpositive_simulated_error(dtype) without return types