Go-mux implements a request router and dispatcher for matching
incoming requests to their respective handler.

The name mux stands for "HTTP request multiplexer". Like the standard
http.ServeMux, mux.Router matches incoming requests against a list of
registered routes and calls a handler for the route that matches the
URL or other conditions. The main features are:

It implements the http.Handler interface so it is compatible with the
standard http.ServeMux.
Requests can be matched based on URL host, path, path prefix, schemes,
header and query values, HTTP methods or using custom matchers.
URL hosts, paths and query values can have variables with an optional
regular expression.
Registered URLs can be built, or "reversed", which helps maintaining
references to resources.
Routes can be used as subrouters: nested routes are only tested if the
parent route matches. This is useful to define groups of routes that
share common conditions like a host, a path prefix or other repeated
attributes. As a bonus, this optimizes request matching.