AddPost { @Override public int hashCode() { int result = name.hashCode(); result = 31 * result + body.hashCode(); return result; } AddPost(@Nonnull String name,
                   @Nonnull String body); @Nonnull String name(); @Nonnull String body(); @Override boolean equals(Object o); @Override int hashCode(); @Override String toString();  }
@Test public void testTwoEqualsPosts_hasSameHashCode() throws Exception { assert_().that(new AddPost("pies", "body").hashCode()) .isEqualTo(new AddPost("pies", "body").hashCode()); }