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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 registration_authority_entity_id(self):
 """ Some entities return the register entity id, but other do not. Unsure if this is a bug or inconsistently registered data. """


        if ATTR_ENTITY_REGISTRATION_AUTHORITY in self.raw:
            try:
                return self.raw[
                    ATTR_ENTITY_REGISTRATION_AUTHORITY][
                    ATTR_ENTITY_REGISTRATION_AUTHORITY_ENTITY_ID][
                    ATTR_DOLLAR_SIGN]
            except KeyError:
                pass