code: def handle_package_has_file(self, package, package_node):
          
          file_nodes = map(self.handle_package_has_file_helper, package.files)
          triples = [(package_node, self.spdx_namespace.hasFile, node) for node in file_nodes]
          for triple in triples:
              self.graph.add(triple)
docs: Add hasFile triples to graph.
          Must be called after files have been added.