gistfile1.php

<?php

class Transfer 
{
  public $field;
}

class Sender 
{
    protected $esp;
    public function __construct($esp)
    {
        $this->esp = $esp;
    }

    public function sendEmail($person)
    {
        $transfer = $this->createTransfer();
        
        $transfer->field = "some data";
        
        return $this->esp->send($transfer);
    }
    
    protected function createTransfer()
    {
       return new Transfer();
    }
}