code: def _pair(x):
      if hasattr(x, "__getitem__"):
          return x
      return x, x
  
imports: import numpy
  from chainer import function_node
  from chainer.utils.conv import col2im_cpu
  from chainer.utils.conv import col2im_gpu
  from chainer.utils.conv import im2col_cpu
  from chainer.utils.conv import im2col_gpu
  from chainer.utils import type_check
label_desc: Use image node_id 1 for calling a global function with example usage: _pair(x) and returns: x,  x, x