code: def link_exceptions(self, custom_exception=None, dashi_exception=None):
          
          if custom_exception is None:
              raise ValueError("custom_exception must be set")
          if dashi_exception is None:
              raise ValueError("dashi_exception must be set")
  
          self._linked_exceptions[custom_exception] = dashi_exception
docs: Link a custom exception thrown on the receiver to a dashi exception