dsl/message.go
func (p *Message) ExpectsToReceive(description string) *Message {
	p.Description = description
	return p
}
func (p *Message) ExpectsToReceive(description string) *Message {
	p.Description = description
	return p
}
// ExpectsToReceive specifies the content it is expecting to be
// given from the Provider. The function must be able to handle this
// message for the interaction to succeed.