Click on "Add Nodes" and then on the graph to add a new node.
Click on "Add Edges" and then drag from one node to another to add
an edge.
Drag to move nodes.
Click on the edit button and then click on nodes, edges or edge
labels to edit.
Click on the delete button and then on nodes, edges, or edge labels
to delete.
Right click on a node to make it the initial/final node,
change/clear its label or delete.
