### Question:
Operations { public static boolean isFileNameValid(String fileName) { if (fileName.endsWith("/")) fileName = fileName.substring(0, fileName.lastIndexOf('/') - 1); if (fileName.contains("/")) fileName = fileName.substring(fileName.lastIndexOf('/') + 1); return !TextUtils.isEmpty(fileName) && !(fileName.contains(ASTERISK) || fileName.contains(BACKWARD_SLASH) || fileName.contains(COLON) || fileName.contains(FOREWARD_SLASH) || fileName.contains(GREATER_THAN) || fileName.contains(LESS_THAN) || fileName.contains(QUESTION_MARK) || fileName.contains(QUOTE)); }  static void mkdir(
      @NonNull final HybridFile file,
      final Context context,
      final boolean rootMode,
      @NonNull final ErrorCallBack errorCallBack); static void mkfile(
      @NonNull final HybridFile file,
      final Context context,
      final boolean rootMode,
      @NonNull final ErrorCallBack errorCallBack); static void rename(
      final HybridFile oldFile,
      final HybridFile newFile,
      final boolean rootMode,
      final Context context,
      final ErrorCallBack errorCallBack); static boolean isCopyLoopPossible(HybridFileParcelable sourceFile, HybridFile targetFile); static boolean isFileNameValid(String fileName);  }### Answer:
@Test public void testIsFileNameValid() { assertTrue(Operations.isFileNameValid("file.txt")); assertTrue(Operations.isFileNameValid("/storage/emulated/0/Documents/file.txt")); assertTrue(Operations.isFileNameValid("/system/etc/file.txt")); assertTrue(Operations.isFileNameValid("smb: assertTrue(Operations.isFileNameValid("ssh: assertTrue(Operations.isFileNameValid("ftp: assertTrue( Operations.isFileNameValid( "content: }