code: @Nonnull
    public static FileIOError deleteFile (@Nonnull final Path aFile)
    {
      ValueEnforcer.notNull (aFile, "Path");
  
      final Path aRealFile = _getUnifiedPath (aFile);
  
      if (!aRealFile.toFile ().isFile ())
        return EFileIOErrorCode.SOURCE_DOES_NOT_EXIST.getAsIOError (EFileIOOperation.DELETE_FILE, aRealFile);
  
      // Is the parent directory writable?
      final Path aParentDir = aRealFile.getParent ();
      if (aParentDir != null && !Files.isWritable (aParentDir))
        return EFileIOErrorCode.SOURCE_PARENT_NOT_WRITABLE.getAsIOError (EFileIOOperation.DELETE_FILE, aRealFile);
  
      return _perform (EFileIOOperation.DELETE_FILE, Files::delete, aRealFile);
    }
docs: Delete an existing file.
  
  @param aFile
  The file to be deleted. May not be <code>null</code>.
  @return A non-<code>null</code> error code.