code: def _as_batch_mat(x):
      return x.reshape(len(x), x.shape[1], -1)
  
imports: import warnings
  import numpy
  from chainer import backend
  from chainer.backends import cuda
  from chainer import function_node
  import chainer.functions
  from chainer import utils
  from chainer.utils import type_check
  import chainerx
label_desc: Use image node_id 2 for calling a global function with example usage: _as_batch_mat(x) and returns: x