@Override
  public long getLong(PropertyKey key) {
    // Low-precision types int can be implicitly converted to high-precision types long
    // without loss of precision
    checkArgument(key.getType() == PropertyKey.PropertyType.LONG
        || key.getType() == PropertyKey.PropertyType.INTEGER);
    return ((Number) get(key)).longValue();
  }
@Test
  public void getLong() {
    // bigger than MAX_INT
    mConfiguration.set(PropertyKey.JOB_MASTER_JOB_CAPACITY, 12345678910L);
    assertEquals(12345678910L,
        mConfiguration.getLong(PropertyKey.JOB_MASTER_JOB_CAPACITY));
  }