code: public String getAbsolutePath() {
          if (isAbsolute()) {
              return path;
          }
          String userDir = System.getProperty("user.dir");
          return path.isEmpty() ? userDir : join(userDir, path);
      }
docs: Returns the absolute path of this file. An absolute path is a path that starts at a root
  of the file system. On Android, there is only one root: {@code /}.
  
  <p>A common use for absolute paths is when passing paths to a {@code Process} as
  command-line arguments, to remove the requirement implied by relative paths, that the
  child must have the same working directory as its parent.