'Generate the version string to be used in static URLs.
``settings`` is the `Application.settings` dictionary and ``path``
is the relative location of the requested asset on the filesystem.
The returned value should be a string, or ``None`` if no version
could be determined.
.. versionchanged:: 3.1
This method was previously recommended for subclasses to override;
`get_content_version` is now preferred as it allows the base
class to handle caching of the result.'

@classmethod
def get_version(cls, settings, path):

    abs_path = cls.get_absolute_path(settings['static_path'], path)
    return cls._get_cached_version(abs_path)
