function LGraph(o) {
        if (LiteGraph.debug) {
            console.log("Graph created");
        }
        this.list_of_graphcanvas = null;
        this.clear();

        if (o) {
            this.configure(o);
        }
    }
******************************************************************************
    // LGraph CLASS
    //*********************************************************************************

    /**
LGraph is the class that contain a full graph. We instantiate one and add nodes to it, and then we can run the execution loop.
supported callbacks:
		+ onNodeAdded: when a new node is added to the graph
		+ onNodeRemoved: when a node inside this graph is removed
		+ onNodeConnectionChange: some connection has changed in the graph (connected or disconnected)

@class LGraph
@constructor
@param {Object} o data from previous serialization [optional]