code: public ContextHandlerBuilder addHandler(Method method, String uriTemplate, RouteHandler handler) {
          if (handler == null) {
              return this;
          }
          return addHandler(Routes.route(method, uriTemplate, handler));
      }
docs: Registers a new handler that will only be called if it matches the given route info (relative to the current context).
  
  @param method      The method to match, or <code>null</code> to accept any method.
  @param uriTemplate A URL template, relative to the context. Supports plain URLs like <code>/abc</code> or paths
  with named parameters such as <code>/abc/{id}</code> or named parameters
  with regexes such as <code>/abc/{id : [0-9]+}</code> where the named
  parameter values can be accessed with the <code>pathParams</code>
  parameter in the route handler.
  @param handler     The handler to invoke if the method and URI matches.
  @return Returns the server builder