added methods to the right branch this time

import itertools

import math

import os

import warnings

            The number of edges or sum of edge weights in the graph.

        """

        s = sum(self.degree(weight=weight).values()) / 2

        if weight is None:

            return math.ceil(s)

        if weight:

            return sum(e[weight] for s, d, e in self.edges_iter(data=True))

        else:

            return s

            return len(self.edges())

    def create_node_subgraph(self, nodes):

        """

        except:

            pass

    def test_size(self):

        graph = self.graph

        self.assertEqual(graph.size(), graph.number_of_edges())

        for u, v, e in graph.edges_iter(data=True):

            e['weight'] = 10

        self.assertEqual(graph.size('weight'), graph.number_of_edges()*10)

    def test_island_nodes(self):

        self.assertEqual(len(self.disconnected_graph.island_nodes()), 1)