Checks if deps were given with argument 'deps' (only for
         old-style getters (not based on decorator).
         Checks types, and returns the value (iterable of strings)
         given with the argument 'deps

def _get_old_style_getter_deps(cls, prop_name, _getter):  # @NoSelf
        """Checks if deps were given with argument 'deps' (only for
         old-style getters (not based on decorator).
         Checks types, and returns the value (iterable of strings)
         given with the argument 'deps'"""
        args, _, _, defaults = inspect.getargspec(_getter)

        try:
            idx = args.index(KWARG_NAME_DEPS) - (len(args) - len(defaults))
            # finds the corresponding value
            if idx < 0:
                raise ValueError("In class %s.%s logical OP getter '%s'"
                                 "must have a default value set for "
                                 "argument '%s'" % \
                                 (cls.__module__, cls.__name__,
                                  _getter.__name__, KWARG_NAME_DEPS))
            _deps = defaults[idx]
            # checks types
            if not hasattr(_deps, '__iter__'):
                raise TypeError("In logical OP getter %s.%s.%s "
                                "default value of argument '%s' "
                                "must be an iterable" % \
                                (cls.__module__, cls.__name__,
                                 _getter.__name__, KWARG_NAME_DEPS))

            for dep in _deps:
                if not isinstance(dep, str):
                    raise TypeError("In logical OP getter %s.%s.%s "
                                    "values of argument '%s' "
                                    "must be strings" % \
                                    (cls.__module__, cls.__name__,
                                     _getter.__name__,
                                     KWARG_NAME_DEPS))
        except ValueError:
            _deps = ()

        return _deps