func NewExpect(name string, arg ...string) (ep *ExpectProcess, err error) {
	// if env[] is nil, use current system env
	return NewExpectWithEnv(name, arg, nil)
}
func NewExpect(name string, arg ...string) (ep *ExpectProcess, err error) {
	// if env[] is nil, use current system env
	return NewExpectWithEnv(name, arg, nil)
}
// NewExpect creates a new process for expect testing.