code: def check_type_forward(self, in_types):
      type_check._argname(in_types, ("x",))
      in_type = in_types[0]
      type_check.expect(max(self.axis1, self.axis2) < in_type.ndim)
      type_check.expect(-in_type.ndim <= min(self.axis1, self.axis2))
  
file_path: chainer/chainer/functions/array/diagonal.py
imports: import numpy
  from chainer import backend
  from chainer import function_node
  from chainer.utils import type_check
label_desc: Use image node_id 2 for calling the Diagonal obj's underlying member method code with example usage: obj.check_type_forward(in_types) without return types