'Return ASN.1 types that are allowed at or past given field position.
Some ASN.1 serialization allow for skipping optional and defaulted fields.
Some constructed ASN.1 types allow reordering of the fields. When recovering
such objects it may be important to know which types can possibly be
present at any given position in the field sets.
Parameters
idx: :py:class:`int`
Field index
Returns
: :class:`~pyasn1.type.tagmap.TagMap`
Map if ASN.1 types allowed at given field position
Raises
: :class:`~pyasn1.error.PyAsn1Error`
If given position is out of fields range'

def getTagMapNearPosition(self, idx):

    try:
        return self.__ambigiousTypes[idx].getTagMap()
    except KeyError:
        raise error.PyAsn1Error('Type    position    out    of    range')
