}

  public void testNull() throws Exception {
    for (Striped<?> striped : allImplementations()) {
      new NullPointerTester().testAllPublicInstanceMethods(striped);
    }
  }

  public void testSizes() {
    // not bothering testing all variations, since we know they share implementations
    assertThat(Striped.lock(100).size()).isAtLeast(100);
    assertTrue(Striped.lock(256).size() == 256);

  }

  public void testNull() throws Exception {
    for (Striped<?> striped : allImplementations()) {
      new NullPointerTester().testAllPublicInstanceMethods(striped);
    }
  }

  public void testSizes() {
    // not bothering testing all variations, since we know they share implementations
    assertThat(Striped.lock(100).size()).isAtLeast(100);
    assertTrue(Striped.lock(256).size() == 256);

      }
      if (!cls.isInterface()) {
        classes.add(cls);
      }
    }
    return classes;
  }

  private static boolean hasTest(Class<?> testClass, Iterable<String> testNames) {
    for (String testName : testNames) {
      try {
        testClass.getMethod(testName);
        return true;
      } catch (NoSuchMethodException e) {
        continue;
      }
    }
    return false;
  }

      writer.write(buf, 0, read);
    }
    reader.close();
    writer.close();

    assertTrue(source.wasStreamClosed());
    assertEquals(STRING, writer.toString());
  }

  public void testLines() throws IOException {
    source = new TestCharSource(LINES);

    ImmutableList<String> lines;
    try (Stream<String> linesStream = source.lines()) {
      assertTrue(source.wasStreamOpened());

      writer.write(buf, 0, read);
    }
    reader.close();
    writer.close();

    assertTrue(source.wasStreamClosed());
    assertEquals(STRING, writer.toString());
  }

  public void testLines() throws IOException {
    source = new TestCharSource(LINES);

    ImmutableList<String> lines;
    try (Stream<String> linesStream = source.lines()) {
      assertTrue(source.wasStreamOpened());

        // Test setting timestamp 1 hour ago
        long testTime = System.currentTimeMillis() - 3600000;
        file.setLastModified(testTime);

        long retrievedTime = file.lastModified();
        // Allow for reasonable precision differences
        assertTrue(Math.abs(retrievedTime - testTime) < 10000, "Set timestamp should be approximately correct");
    }