func (c *Context) Destroy() {
	delete(memo, c.req)
}
Remove a Context from the memo map
package context
import (
	"net/http"
	"sync"
)
type Context struct {
	req  *http.Request
	vars map[string]string
}
var (
	mutex sync.RWMutex
	memo  = make(map[*http.Request]Context)
)
func NewContext(req *http.Request) *Context {
	memo[req] = Context{req, make(map[string]string)}
	c := memo[req]
	return &c
}
func Find(req *http.Request) *Context {
	c := memo[req]
	if c.req != nil {
		con := memo[req]
		return &con
	}
	return nil
}
func (c *Context) Set(key, value string) {
	mutex.Lock()
	c.vars[key] = value
	mutex.Unlock()
}
func (c *Context) Get(key string) string {
	return c.vars[key]
}
func (c *Context) GetAll() map[string]string {
	return c.vars
}
func (c *Context) Delete(key string) {
	delete(c.vars, key)
}