code: @Test public void getFilteredJarFile() throws Exception {
    JarFile filteredJarFile=this.jarFile.getFilteredJarFile(new JarEntryFilter(){
      @Override public AsciiBytes apply(    AsciiBytes entryName,    JarEntryData entry){
        if (entryName.toString().equals("1.dat")) {
          return new AsciiBytes("x.dat");
        }
        return null;
      }
    }
  );
    Enumeration<java.util.jar.JarEntry> entries=filteredJarFile.entries();
    assertThat(entries.nextElement().getName(),equalTo("x.dat"));
    assertThat(entries.hasMoreElements(),equalTo(false));
    InputStream inputStream=filteredJarFile.getInputStream(filteredJarFile.getEntry("x.dat"));
    assertThat(inputStream.read(),equalTo(1));
    assertThat(inputStream.read(),equalTo(-1));
  }
  