code: def _random_array(xp, shape):
      return xp.array(
          np.random.uniform(-1, 1, size=shape), dtype=np.float32
      )
  
imports: from __future__ import division
  import numpy
  import unittest
  import chainer
  from chainer import testing
  from chainer.testing import attr
  from chainercv.links.model.fpn import bbox_head_loss_post
  from chainercv.links.model.fpn import bbox_head_loss_pre
  from chainercv.links.model.fpn import BboxHead
label_desc: Use image node_id 1 for calling a global function with example usage: _random_array(xp, shape) and returns: xp