     describe "get_node_coordinates method", ->
 
       it "should return node coords if exist", ->
-        graph_source = new GraphDataSource()
+        graph_source = new GraphSource()
         graph_source.nodes.data.index = [0,1,2,3]
 
         [xs, ys] = @layout_provider.get_node_coordinates(graph_source)

    describe "get_node_coordinates method", ->

      it "should return edge coords if exist", ->
        graph_source = new GraphDataSource()
        graph_source.nodes.data.index = [0,1,2,3]
        graph_source.edges.data.start = [0,0,0]
        graph_source.edges.data.end = [1,2,3]

        expect(ys).to.be.deep.equal([0,1,0,-1])

      it "should return nulls if coords don't exist", ->
        graph_source = new GraphSource()
        graph_source.nodes.data.index = [4,5,6]

        [xs, ys] = @layout_provider.get_node_coordinates(graph_source)
