code: func (g *Graph) RemoveEdge(edge Edge) {
  	g.init()
  	g.debug.RemoveEdge(edge)
  
  	// Delete the edge from the set
  	g.edges.Delete(edge)
  
  	// Delete the up/down edges
  	if s, ok := g.downEdges[hashcode(edge.Source())]; ok {
  		s.Delete(edge.Target())
  	}
  	if s, ok := g.upEdges[hashcode(edge.Target())]; ok {
  		s.Delete(edge.Source())
  	}
  }
docs: // RemoveEdge removes an edge from the graph.