def modify_symbol(sym: ast.Symbol, scope: ast.InstanceClass) -> None:
    """
    Apply a modification to a symbol if the scope matches (or is None)
    :param sym: symbol to apply modifications for
    :param scope: scope of modification
    """

    # We assume that we do not screw up the order of applying modifications
    # when "moving up" with the scope.
    apply_args = [x for x in sym.class_modification.arguments
                  if x.scope is None or x.scope.full_reference().to_tuple() == scope.full_reference().to_tuple()]
    skip_args = [x for x in sym.class_modification.arguments
                 if x.scope is not None and x.scope.full_reference().to_tuple() != scope.full_reference().to_tuple()]

    for class_mod_argument in apply_args:
        argument = class_mod_argument.value

        assert isinstance(argument, ast.ElementModification), \
            "Found redeclaration modification which should already have been handled."

        # TODO: Strip all non-symbol stuff.
        if argument.component.name not in ast.Symbol.ATTRIBUTES:
            raise Exception("Trying to set unknown symbol property {}".format(argument.component.name))

        setattr(sym, argument.component.name, argument.modifications[0])

    sym.class_modification.arguments = skip_args