protocol

var (
	//ErrNilResult is of type error
	ErrNilResult = errors.New("result is nil")
	//ErrUnknown is of type string which returns unknown error
	ErrUnknown = ProxyError{"Unknown Error,instance is not selected, error is nil"}
	//ErrUnExpectedHandlerChainResponse is of type string which returns unexpected handler error
	ErrUnExpectedHandlerChainResponse = ProxyError{"Response from Handler chain is nil,better to check if handler chain is empty, or some handler just return a nil response"}
)