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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def read(self, entity=None, attrs=None, ignore=None, params=None):
 """Ignore usergroup from read and alter auth_source_ldap with auth_source """

        if entity is None:
            entity = type(self)(
                self._server_config,
                usergroup=self.usergroup,  # pylint:disable=no-member
            )
        if ignore is None:
            ignore = set()
        ignore.add('usergroup')
        if attrs is None:
            attrs = self.read_json()
        attrs['auth_source'] = attrs.pop('auth_source_ldap')
        return super(ExternalUserGroup, self).read(entity, attrs, ignore, params)