def removeAssociation(self, server_url, handle):
        """Remove an association if it exists. Do nothing if it does not.

        (str, str) -> bool
        """
        assoc = self.getAssociation(server_url, handle)
        if assoc is None:
            return 0
        else:
            filename = self.getAssociationFilename(server_url, handle)
            return _removeIfPresent(filename)
Remove an association if it exists. Do nothing if it does not.

        (str, str) -> bool