// append add a contextMiddleware to the chain.
append add a contextMiddleware to the chain.
// append add a contextMiddleware to the chain .
func (chain *Chain) append(cm ContextMiddleware) (newChain *Chain) {
	newChain = NewChain(cm)
	newChain.parent = chain
	return newChain
}
func ( chain * Chain ) append ( cm ContextMiddleware ) ( newChain * Chain ) { newChain = NewChain ( cm ) newChain . parent = chain return newChain }
append add a contextMiddleware to the chain.
append add a contextMiddleware to the chain .