### Question:
JdbcHighWaterMarkAccumulableParam implements AccumulableParam<JdbcHighWaterMark, Long>, Serializable { @Nonnull @Override public JdbcHighWaterMark zero(@Nonnull final JdbcHighWaterMark template) { return new JdbcHighWaterMark(); }  @Nonnull @Override JdbcHighWaterMark addAccumulator(@Nonnull final JdbcHighWaterMark accumulator, @Nullable final Long value); @Nonnull @Override JdbcHighWaterMark addInPlace(@Nonnull final JdbcHighWaterMark left, @Nonnull final JdbcHighWaterMark right); @Nonnull @Override JdbcHighWaterMark zero(@Nonnull final JdbcHighWaterMark template);  }### Answer:
@Test public void zero() { final JdbcHighWaterMark template = new JdbcHighWaterMark("mockWaterMark", Mockito.mock(KyloCatalogClient.class)); final JdbcHighWaterMark zero = new JdbcHighWaterMarkAccumulableParam().zero(template); Assert.assertNull("Expected high water mark value to be null", zero.getValue()); }