added doc tests and an index function
added doc tests and an index function

armandobs14/rdflib,RDFLib/rdflib,marma/rdflib,avorio/rdflib,marma/rdflib,avorio/rdflib,marma/rdflib,armandobs14/rdflib,ssssam/rdflib,armandobs14/rdflib,dbs/rdflib,yingerj/rdflib,marma/rdflib,avorio/rdflib,dbs/rdflib,armandobs14/rdflib,dbs/rdflib,dbs/rdflib,ssssam/rdflib,ssssam/rdflib,yingerj/rdflib,yingerj/rdflib,yingerj/rdflib,RDFLib/rdflib,RDFLib/rdflib,ssssam/rdflib,avorio/rdflib,RDFLib/rdflib