code: def as_mat(x):
      warnings.warn(
          "chainer.utils.array.as_mat is deprecated. Please refer to "
          "numpy.reshape or other array backend functions to reshape ndarrays.",
          DeprecationWarning,
      )
      if x.ndim == 2:
          return x
      return x.reshape(len(x), -1)
  
file_path: chainer/chainer/utils/array.py
imports: import warnings
  import numpy
  import six
  import chainer
  from chainer.backends import cuda
label_desc: Use image node_id 2 for calling a global function with example usage: as_mat(x) and returns: x, x