ServeMux is an HTTP request multiplexer. The HandleFunc we used in the preceding section is actually a method of ServeMux. By creating a new ServeMux, we can handle multiple routes. Before that, we can also create our own multiplexer. A multiplexer just handles the logic of separating routes with a function called ServeHTTP. So if we create a new struct with the ServeHTTP method, it can do the job.
Consider a route as a key in a dictionary (map), then the handler as its value. The router finds the handler from the route and tries to execute the ServeHTTP function. Let us create a program called customMux.go and see this implementation in action:
package main
import (
"fmt"
"math/rand"
"net/http"
)
// CustomServeMux is a struct which can be a multiplexer
type CustomServeMux struct {
}
// This is the function...
