code: def tuples_to_coll(cls, generator, coerce=False):
          
          if cls != Collection:
              raise exc.CollectionDefinitionError(
                  property='tuples_to_coll',
                  coll='Collection',
              )
docs: *required virtual method* This class method, part of the sub-class
          API, converts a generator of ``(K, V)`` tuples (the *tuple protocol*)
          to one of the underlying collection type.