How to use the pyisemail.utils.enum function in pyIsEmail

import re
import sys
from pyisemail import EmailValidator
from pyisemail.diagnosis import BaseDiagnosis, CFWSDiagnosis
from pyisemail.diagnosis import DeprecatedDiagnosis
from pyisemail.diagnosis import InvalidDiagnosis, RFC5321Diagnosis
from pyisemail.diagnosis import RFC5322Diagnosis, ValidDiagnosis
from pyisemail.utils import enum

__all__ = ["ParserValidator"]

Char = enum(AT='@',
            BACKSLASH='\\',
            DOT='.',
            DQUOTE='"',
            OPENPARENTHESIS='(',
            CLOSEPARENTHESIS=')',
            OPENSQBRACKET='[',
            CLOSESQBRACKET=']',
            HYPHEN='-',
            COLON=':',
            DOUBLECOLON='::',
            SP=' ',
            HTAB="\t",
            CR="\r",
            LF="\n",
            IPV6TAG='IPv6:',
            # US-ASCII visible characters not valid for atext

CLOSEPARENTHESIS=')',
            OPENSQBRACKET='[',
            CLOSESQBRACKET=']',
            HYPHEN='-',
            COLON=':',
            DOUBLECOLON='::',
            SP=' ',
            HTAB="\t",
            CR="\r",
            LF="\n",
            IPV6TAG='IPv6:',
            # US-ASCII visible characters not valid for atext
            # (http:#tools.ietf.org/html/rfc5322#section-3.2.3)
            SPECIALS='()<>[]:;@\\,."')

Context = enum(LOCALPART=0,
               DOMAIN=1,
               LITERAL=2,
               COMMENT=3,
               FWS=4,
               QUOTEDSTRING=5,
               QUOTEDPAIR=6)

if sys.version_info[0] == 3:
    _unichr = chr
    _range = range
elif sys.version_info[0] == 2:
    _unichr = unichr
    _range = xrange


def to_char(token):