'Copies the object, applying a new tagging to it
:param tag_type:
A unicode string of "implicit" or "explicit"
:param tag:
A integer tag number
:return:
An Asn1Value object'

def retag(self, tag_type, tag):

    new_obj = self.__class__(tag_type=tag_type, tag=tag)
    new_obj._copy(self, copy.deepcopy)
    return new_obj
