Pop\Mail\Mail::setSubject PHP Method

    public function setSubject($subj)
    {
        $this->subject = $subj;
        return $this;
    }

 public function testSetAndGetSubject()
 {
     $m = new Mail();
     $m->setSubject('Hello World');
     $this->assertEquals('Hello World', $m->getSubject());
 }