code: def compute_mean(is_module, xp, a, axis):
      return xp.mean(a, axis) if is_module else a.mean(axis)
  
imports: import chainer
  import numpy
  import pytest
  import chainerx
  import chainerx.testing
  from chainerx_tests import array_utils
  from chainerx_tests import dtype_utils
  from chainerx_tests import math_utils
  from chainerx_tests import op_utils
label_desc: Use image node_id 6 for calling a global function with example usage: compute_mean(is_module, xp, a, axis) and returns: unknown