code: def split(x, axis=0):
      
      from .function_bases import split as split_base
      return split_base(x, axis, x.shape[axis])
docs: Split arrays at the specified axis.
  
      It returns a number corresponding the size of the given
      axis (i.e ``x.shape[axis]``) of :obj:`~nnabla.Variable` s.
  
      Args:
          x(~nnabla.Variable): N-D array
          axis(int): Axis
  
      Returns: A :obj:`tuple` of :obj:`~nnabla.Variable` s
  
      See Also:
          :func:`nnabla.function_bases.split`.