How to use the pydoctor.sphinx.SphinxInventory function in pydoctor

class HeadRequest(urllib2.Request, object):
    """
    A request for the HEAD HTTP method.
    """

    def get_method(self):
        """
        Use the HEAD HTTP method.
        """
        return 'HEAD'



class TwistedSphinxInventory(SphinxInventory):
    """
    Custom SphinxInventory to work around broken external references to
    Sphinx.

    All exceptions should be reported upstream and a comment should be created
    with a link to the upstream report.
    """

    def getLink(self, name):
        """
        Resolve the full URL for a cross reference.

        @param name: Value of the cross reference.
        @type name: L{str}

        @return: A full URL for the I{name} reference or L{None} if no link was

class HeadRequest(urllib2.Request):
    """
    A request for the HEAD HTTP method.
    """

    def get_method(self):
        """
        Use the HEAD HTTP method.
        """
        return 'HEAD'



class TwistedSphinxInventory(SphinxInventory):
    """
    Custom SphinxInventory to work around broken external references to
    Sphinx.

    All exceptions should be reported upstream and a comment should be created
    with a link to the upstream report.
    """

    def getLink(self, name):
        """
        Resolve the full URL for a cross reference.

        @param name: Value of the cross reference.
        @type name: L{str}

        @return: A full URL for the I{name} reference or L{None} if no link was