code: func (g *Graph) Delete(n interface{}) {
  
  	if g == nil {
  		return
  	}
  	for i := 0; i < g.Len(); i++ {
  		if g.Out[i].This == n {
  			if i < (g.Len() - 1) {
  				g.Out = append(g.Out[:i], g.Out[i+1:]...)
  			} else {
  				g.Out = g.Out[:i]
  			}
  			i--
  		}
  	}
  }
docs: // Delete removes all subnodes with the given content