text: version_info = (2, 3, 0, 'final')
  
  _specifier_ = {'alpha': 'a', 'beta': 'b', 'candidate': 'rc', 'final': '', 'dev': 'dev'}
  
  postfix = ''
  if version_info[3] != 'final':
      if version_info[3] == 'dev' and len(version_info) < 5:
          postfix = 'dev0'
      else:
          postfix = _specifier_[version_info[3]] + str(version_info[4])
  
  __version__ = '%s.%s.%s%s' % (version_info[0], version_info[1], version_info[2], postfix)
  
  
  # The version of the attribute spec that this package
  # implements. This is the value used in
  # _model_module_version/_view_module_version.
  #
  # Update this value when attributes are added/removed from
  # the widget models, or if the serialized format changes.
  #
  # The major version needs to match that of the JS package.
  EXTENSION_SPEC_VERSION = '^2.1.0'
  