AsnMetaMember

    class AsnMetaMember(AsnNode)
       This class stores the semantic content of a member type of a
       CHOICE or SEQUENCE.
       Members:
           _isOptional : if True, node is optional
           _containedType : the contained element as a string (type name)

All nodes of the ASN.1 Abstract Syntax Tree inherit from AsnNode, which offers the Location() member: if something must be reported that pertains to the specifics of the ASN.1 type, the backends can report the whereabouts of the type by printing the string return by Location().