code: func (p *Pushover) SendMessage(message *Message, recipient *Recipient) (*Response, error) {
  	// Validate pushover
  	if err := p.validate(); err != nil {
  		return nil, err
  	}
  
  	// Validate recipient
  	if err := recipient.validate(); err != nil {
  		return nil, err
  	}
  
  	// Validate message
  	if err := message.validate(); err != nil {
  		return nil, err
  	}
  
  	return message.send(p.token, recipient.token)
  }
docs: // SendMessage is used to send message to a recipient.