EDD\HelpScout\Request::signature_equals PHP Method

    public function signature_equals($signature)
    {
        // use `hash_equals( str1, str2 )` if it exists
        if (function_exists('hash_equals')) {
            return hash_equals($this->signature, $signature);
        }
        return $this->signature === $signature;
    }

 /**
  * @covers Request::signature_equals
  */
 public function test_signature_equals()
 {
     $data = ['key' => 'value'];
     $request = new Request($data);
     $signature = base64_encode(hash_hmac('sha1', json_encode($data), HELPSCOUT_SECRET_KEY, true));
     self::assertTrue($request->signature_equals($signature));
     self::assertFalse($request->signature_equals(''));
     $signature = base64_encode(hash_hmac('sha1', json_encode(['other-key' => 'value']), HELPSCOUT_SECRET_KEY, true));
     self::assertFalse($request->signature_equals($signature));
 }