code: public TarEntry[] getDirectoryEntries() throws InvalidHeaderException {
          if (this.file == null || !this.file.isDirectory()) {
              return new TarEntry[0];
          }
  
          String[] list = this.file.list();
  
          TarEntry[] result = new TarEntry[list.length];
  
          for (int i = 0; i < list.length; ++i) {
              result[i] = new TarEntry(new File(this.file, list[i]));
          }
  
          return result;
      }
docs: If this entry represents a file, and the file is a directory, return an array of TarEntries for this entry's
  children.
  
  @return An array of TarEntry's for this entry's children.