default_context.go
func (d *DefaultContext) Param(key string) string {
	return d.Params().Get(key)
}
func (d *DefaultContext) Param(key string) string {
	return d.Params().Get(key)
}
func ( d * DefaultContext ) Param ( key string ) string { return d . Params ( ) . Get ( key ) }
// Param returns a param, either named or query string,
// based on the key.
Param returns a param either named or query string based on the key .