Initialise arguments effects as this analyse is inter-procedural.

        Initialisation done for Pythonic functions and default value set for
        user defined functions.

def prepare(self, node):
        """
        Initialise arguments effects as this analyse is inter-procedural.

        Initialisation done for Pythonic functions and default value set for
        user defined functions.
        """
        super(ArgumentEffects, self).prepare(node)
        for n in self.global_declarations.values():
            fe = FunctionEffects(n)
            self.node_to_functioneffect[n] = fe
            self.result.add_node(fe)