old_contents: """
  Marshmallow-3 dropped support for Python-2.
  This file keeps backwards support for older MA versions.
  """
  
  import sys
  
  PY2 = int(sys.version_info[0]) == 2
  
  if PY2:
      text_type = unicode  # noqa
  else:
      text_type = str
  
  
  # From six
  def with_metaclass(meta, *bases):
      """Create a base class with a metaclass."""
      # This requires a bit of explanation: the basic idea is to make a dummy
      # metaclass for one level of class instantiation that replaces itself with
      # the actual metaclass.
      class metaclass(meta):  # noqa
  
          def __new__(cls, name, this_bases, d):
              return meta(name, bases, d)
      return type.__new__(metaclass, 'temporary_class', (), {})
  
new_contents: """
  marshmallow 3 dropped support for Python 2.
  This file keeps backwards support for older MA versions.
  """
  
  import sys
  
  PY2 = int(sys.version_info[0]) == 2
  
  if PY2:
      text_type = unicode  # noqa
  else:
      text_type = str
  
  
  # From six
  def with_metaclass(meta, *bases):
      """Create a base class with a metaclass."""
      # This requires a bit of explanation: the basic idea is to make a dummy
      # metaclass for one level of class instantiation that replaces itself with
      # the actual metaclass.
      class metaclass(meta):  # noqa
  
          def __new__(cls, name, this_bases, d):
              return meta(name, bases, d)
      return type.__new__(metaclass, 'temporary_class', (), {})
  
subject: Update marshmallow_peewee/_compat.py