Bitpay\SinKey::setPublicKey PHP Method

    public function setPublicKey(PublicKey $publicKey)
    {
        $this->publicKey = $publicKey;
        return $this;
    }

 /**
  * @return SinKey
  */
 public function getSin()
 {
     if (empty($this->hex)) {
         $this->generate();
     }
     if (null === $this->sin) {
         $this->sin = new SinKey();
         $this->sin->setPublicKey($this);
         $this->sin->generate();
     }
     return $this->sin;
 }