code: def _buildGraph(self):
          
          for n in self.namespaces:
              self.rdflib_graph.bind(n[0], rdflib.Namespace(n[1]))
          if self.triples:
              for terzetto in self.triples:
                  self.rdflib_graph.add(terzetto)
docs: transforms the triples list into a proper rdflib graph
          (which can be used later for querying)