code: def _func_class(func):
      if isinstance(func, function.Function):
          return func.__class__
      else:
          name = func.__name__.capitalize()
          return getattr(functions, name, None)
  
file_path: chainer/chainer/testing/unary_math_function_test.py
imports: import unittest
  import warnings
  import numpy
  from chainer.backends import cuda
  from chainer import function
  from chainer import functions
  from chainer import variable
label_desc: Use image node_id 4 for calling a global function with example usage: _func_class(func) and returns: func, getattr