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: collection.go
    path of file: ./repos/tiedot/httpapi
    
    the code of the file until where you have to start completion: // Collection management handlers.

package httpapi

import (
	"encoding/json"
	"fmt"
	"net/http"
)

// Create a collection.
func Create(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Cache-Control", "must-revalidate")
	w.Header().Set("Content-Type", "text/plain")
	w.Header().Set("Access-Control-Allow-Origin", "*")
	w.Header().Set("Access-Control-Allow-Methods", "POST, GET, PUT, OPTIONS")
	var col string
	if !Require(w, r, "col", &col) {
		return
	}
	if err 
    
func Scrub(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Cache-Control", "must-revalidate")
	w.Header().Set("Content-Type", "text/plain")
	w.Header().Set("Access-Control-Allow-Origin", "*")
	w.Header().Set("Access-Control-Allow-Methods", "POST, GET, PUT, OPTIONS")
	var col string
	if !Require(w, r, "col", &col) {
		return
	}
	dbCol := HttpDB.Use(col)
	if dbCol == nil {
		http.Error(w, fmt.Sprintf("Collection %s does not exist", col), http.StatusBadRequest)
	} else {
		HttpDB.Scrub(col)
	}
}