public function testConvertHexStringToString() { $enc = new \Com\Tecnick\Pdf\Encrypt\Encrypt(); $result = $enc->convertHexStringToString(''); $this->assertEquals('', $result); $result = $enc->convertHexStringToString('68656c6c6f20776f726c64'); $this->assertEquals('hello world', $result); $result = $enc->convertHexStringToString('68656c6c6f20776f726c642'); $this->assertEquals('hello world ', $result); }