Maybe we can use AST rewrite to replace file rewrite

[atlas-comstock]

				// try rewrite the reduce function call
				/*TODO: useless
				switch x := ret.Fun.(type) {
				case *ast.Ident:
					x.Name = "targetpkg." + newFunName
					ret.Fun = x
				case *ast.SelectorExpr:
					x.X.(*ast.Ident).Name = "targetpkg"
					x.Sel.Name = newFunName
					fmt.Println("my..................", x.Sel.Name)
					ret.Fun = x
				}
				cr.Replace(ret)
				if err := format.Node(os.Stdout, token.NewFileSet(), n); err != nil {
					log.Fatalln("Error:", err)
				}
				*/