class_docstr: Test for niftynet.layer.subpixel.SubPixelLayer.
  Mostly adapted from convolution_test.py
code: def _make_output_shape(self, data, upsampling):
      data_shape = data.shape.as_list()
      output_shape = [data_shape[0]]
      output_shape += [upsampling * d for d in data_shape[1:-1]]
      output_shape += [
          data_shape[-1] // (upsampling ** (len(data_shape) - 2))
      ]
      return output_shape
  
file_path: NiftyNet/tests/subpixel_test.py
imports: from __future__ import division, absolute_import, print_function
  import functools
  import numpy
  import tensorflow
  from niftynet.layer.subpixel import SubPixelLayer
  from tests.niftynet_testcase import NiftyNetTestCase
label_desc: Use image node_id 3 for calling the SubPixelTest obj's underlying member method code with example usage: obj._make_output_shape(data, upsampling) and returns: output_shape