def __init__(self, db_node_class, current_node_class_registry):
self.db_node_class = db_node_class<EOL>self.current_node_class_registry = current_node_class_registry<EOL>
Initialises the exception with the database node that caused the missmatch.

:param db_node_class: Depending on the concrete class, this is either a Neo4j driver node object
       from the DBMS, or a data model class from an application's hierarchy.
:param current_node_class_registry: Dictionary that maps frozenset of
       node labels to model classes