code: func AllowRequestsFrom(allowedOrigins ...string) http.HandlerFunc {
  	c := &CORS{
  		AllowOrigins: allowedOrigins,
  		AllowMethods: []string{"GET", "POST"},
  		AllowHeaders: []string{"Origin", "Content-Type"},
  		ContentType:  "application/json; charset=utf-8",
  	}
  
  	c.generatePatterns()
  
  	return func(w http.ResponseWriter, req *http.Request) {
  		origin := req.Header.Get("Origin")
  		if c.isOriginAllowed(origin) {
  			w.Header().Set("Access-Control-Allow-Origin", origin)
  			w.Header().Set("Access-Control-Allow-Headers", c.AllowedHeaders())
  			w.Header().Set("Access-Control-Allow-Methods", c.AllowedMethods())
  			w.Header().Set("Content-Type", c.ContentType)
  		}
  	}
  }
docs: // AllowRequestsFrom returns handler to verify that requests come from allowedOrigins