Jose\KeyConverter\ECKey::loadPrivatePEM PHP Method

    private function loadPrivatePEM(array $children)
    {
        $this->verifyVersion($children[0]);
        $x = null;
        $y = null;
        $d = $this->getD($children[1]);
        $this->getXAndY($children[3], $x, $y);
        Assertion::isInstanceOf($children[2], ExplicitlyTaggedObject::class, 'Unable to load the key');
        Assertion::isArray($children[2]->getContent(), 'Unable to load the key');
        Assertion::isInstanceOf($children[2]->getContent()[0], ObjectIdentifier::class, 'Unable to load the key');
        $curve = $children[2]->getContent()[0]->getContent();
        $this->private = true;
        $this->values['kty'] = 'EC';
        $this->values['crv'] = $this->getCurve($curve);
        $this->values['d'] = Base64Url::encode(hex2bin($d));
        $this->values['x'] = Base64Url::encode(hex2bin($x));
        $this->values['y'] = Base64Url::encode(hex2bin($y));
    }