Memorizes a class attribute

def _onClassAttribute(self, name, line, pos, absPosition, level):
        """Memorizes a class attribute"""
        # A class must be on the top of the stack
        attributes = self.objectsStack[level].classAttributes
        for item in attributes:
            if item.name == name:
                return
        attributes.append(ClassAttribute(name, line, pos, absPosition))