You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: btree_mem.go
    path of file: ./repos/cloud-torrent/vendor/github.com/google/btree
    
    the code of the file until where you have to start completion: // Copyright 2014 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express 
    
func main() {
	flag.Parse()
	vals := rand.Perm(*size)
	var t, v interface{}
	v = vals
	var stats runtime.MemStats
	for i := 0; i < 10; i++ {
		runtime.GC()
	}
	fmt.Println("-------- BEFORE ----------")
	runtime.ReadMemStats(&stats)
	fmt.Printf("%+v\n", stats)
	start := time.Now()
	if *gollrb {
		tr := llrb.New()
		for _, v := range vals {
			tr.ReplaceOrInsert(llrb.Int(v))
		}
		t = tr // keep it around
	} else {
		tr := btree.New(*degree)
		for _, v := range vals {
			tr.ReplaceOrInsert(btree.Int(v))
		}
		t = tr // keep it around
	}
	fmt.Printf("%v inserts in %v\n", *size, time.Since(start))
	fmt.Println("-------- AFTER ----------")
	runtime.ReadMemStats(&stats)
	fmt.Printf("%+v\n", stats)
	for i := 0; i < 10; i++ {
		runtime.GC()
	}
	fmt.Println("-------- AFTER GC ----------")
	runtime.ReadMemStats(&stats)
	fmt.Printf("%+v\n", stats)
	if t == v {
		fmt.Println("to make sure vals and tree aren't GC'd")
	}
}