Add name of class to error message

pysv/model.py

@@ -28,7 +28,7 @@ def check_class_ctor(cls: type):
         # make sure that it doesn't have any extra parameters
         signature = inspect.signature(ctor)
         assert len(signature.parameters) == 1, """Class constructor has more arguments than simple
-self is required to have @sv decorator"""
+self{0} is required to have @sv decorator""".format(cls.__name__)
         # generate a wrapper
 
         # need to be careful about the imports. seems all the functions have the same scope, we pick the one