old_contents: # encoding: utf-8
  
  """
  .. codeauthor:: Tsuyoshi Hombashi <tsuyoshi.hombashi@gmail.com>
  """
  
  from __future__ import absolute_import, unicode_literals
  
  from .error import NullNameError
  
  
  def _validate_null_string(text, error_msg="null name"):
      if is_not_null_string(text):
          return
  
      if is_null_string(text):
          raise NullNameError(error_msg)
  
      raise TypeError("text must be a string: actual={}".format(type(text)))
  
  
  def _preprocess(name):
      return name.strip()
  
  
  def is_null_string(value):
      if value is None:
          return True
  
      try:
          return len(value.strip()) == 0
      except AttributeError:
          return False
  
  
  def is_not_null_string(value):
      try:
          return len(value.strip()) > 0
      except AttributeError:
          return False
  
  
  def get_unprintable_char_list():
      import six
      import string
  
      return [six.unichr(c) for c in range(256) if chr(c) not in string.printable]
  
  
  unprintable_char_list = get_unprintable_char_list()
  
new_contents: # encoding: utf-8
  
  """
  .. codeauthor:: Tsuyoshi Hombashi <tsuyoshi.hombashi@gmail.com>
  """
  
  from __future__ import absolute_import, unicode_literals
  
  from .error import NullNameError
  
  
  def _validate_null_string(text, error_msg="null name"):
      if is_not_null_string(text):
          return
  
      if is_null_string(text):
          raise NullNameError(error_msg)
  
      raise TypeError("text must be a string: actual={}".format(type(text)))
  
  
  def _preprocess(name):
      return name.strip()
  
  
  def is_null_string(value):
      if value is None:
          return True
  
      try:
          return len(value.strip()) == 0
      except AttributeError:
          return False
  
  
  def is_not_null_string(value):
      try:
          return len(value.strip()) > 0
      except AttributeError:
          return False
  
  
  def get_unprintable_ascii_char_list():
      import six
      import string
  
      return [six.unichr(c) for c in range(256) if chr(c) not in string.printable]
  
  
  unprintable_char_list = get_unprintable_ascii_char_list()
  
subject: Rename a function