* natural ordering of the elements, if there is no comparator) to test element equality. As a
 * result, if the comparator is not consistent with equals, some of the standard implementations may
 * violate the {@code Set} contract.
 *
 * <p>The {@code standard} methods and the collection views they return are not guaranteed to be
 * thread-safe, even when all of the methods that they depend on are thread-safe.
 *

 * natural ordering of the elements, if there is no comparator) to test element equality. As a
 * result, if the comparator is not consistent with equals, some of the standard implementations may
 * violate the {@code Set} contract.
 *
 * <p>The {@code standard} methods and the collection views they return are not guaranteed to be
 * thread-safe, even when all of the methods that they depend on are thread-safe.
 *

 *
 * <p><b>Warning:</b> The comparison must be <i>consistent with equals</i> as explained by the
 * {@link Comparable} class specification. Otherwise, the resulting multiset will violate the {@link
 * Collection} contract, which is specified in terms of {@link Object#equals}.
 *
 * <p>See the Guava User Guide article on <a href=

 *
 * <p><b>Warning:</b> The comparison must be <i>consistent with equals</i> as explained by the
 * {@link Comparable} class specification. Otherwise, the resulting multiset will violate the {@link
 * Collection} contract, which is specified in terms of {@link Object#equals}.
 *
 * <p>See the Guava User Guide article on <a href=

 * elements, if there is no comparator) to test element equality. As a result, if the comparator is
 * not consistent with equals, some of the standard implementations may violate the {@code Set}
 * contract.
 *
 * <p>The {@code standard} methods and the collection views they return are not guaranteed to be
 * thread-safe, even when all of the methods that they depend on are thread-safe.
 *

  }
}
```

### Rewriting Responses

Symmetrically, interceptors can rewrite response headers and transform the response body. This is generally more dangerous than rewriting request headers because it may violate the webserver's expectations!

 * instances.
 *
 * <p><b>Warning:</b> The comparators or comparables used must be <i>consistent with equals</i> as
 * explained by the {@link Comparable} class specification. Otherwise, the resulting multiset will
 * violate the general contract of {@link SetMultimap}, which is specified in terms of {@link
 * Object#equals}.
 *
 * <p>The collections returned by {@code keySet} and {@code asMap} iterate through the keys

 * elements, if there is no comparator) to test element equality. As a result, if the comparator is
 * not consistent with equals, some of the standard implementations may violate the {@code Set}
 * contract.
 *
 * <p>The {@code standard} methods and the collection views they return are not guaranteed to be
 * thread-safe, even when all of the methods that they depend on are thread-safe.
 *

   * level than the whole method but without performing a runtime null check. That way, we can still
   * pass null inputs to LegacyConverter, and it can violate the contract of Converter.
   *
   * TODO(cpovirk): Could this be simplified if we modified implementations of LegacyConverter to
   * override methods (probably called "unsafeDoForward" and "unsafeDoBackward") with the same

   * level than the whole method but without performing a runtime null check. That way, we can still
   * pass null inputs to LegacyConverter, and it can violate the contract of Converter.
   *
   * TODO(cpovirk): Could this be simplified if we modified implementations of LegacyConverter to
   * override methods (probably called "unsafeDoForward" and "unsafeDoBackward") with the same