def resolveEntity(self, publicId, systemId):
        source = InputSource()
        source.setSystemId(systemId)
        try:
            dtdPath = self.knownDTDs[systemId]
        except __HOLE__:
            raise process.ProcessingFailure(
                "Invalid DTD system identifier (%r) in %s.  Only "
                "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd "
                "is allowed." % (systemId, self.filename))
        source.setByteStream(dtdPath.open())
        return source
dataset/ETHPy150Open nlloyd/SubliminalCollaborator/libs/twisted/lore/tree.py/_LocalEntityResolver.resolveEntity