code: def ref_split(x, axis):
      return tuple(
          [
              np.squeeze(sq, axis)
              for sq in np.split(x, x.shape[axis], axis=axis)
          ]
      )
  
file_path: nnabla/python/test/function/test_split.py
imports: import pytest
  import numpy
  import nnabla
  import nnabla.functions
  from nbla_test_utils import list_context
label_desc: Use image node_id 1 for calling a global function with example usage: ref_split(x, axis) and returns: tuple