:octocat: Byte: string "0" fails with empty()

src/Data/Byte.php

@@ -38,7 +38,7 @@ final class Byte extends QRDataModeAbstract{
 	 * @inheritDoc
 	 */
 	public static function validateString(string $string):bool{
-		return !empty($string);
+		return $string !== '';
 	}
 
 	/**

tests/Data/ByteTest.php

@@ -27,6 +27,7 @@ final class ByteTest extends DatainterfaceTestAbstract{
 		return [
 			["\x01\x02\x03", true],
 			['            ', true], // not empty!
+			['0', true], // should survive !empty()
 			['', false],
 		];
 	}