tree c39705845b02f05be8676450ea976c1cf5bad62f
parent db96686b3669707dcefa4f93ac2c2eaf9458fb1b
author Dave Borowitz <dborowitz@google.com> 1489069494 -0500
committer Dave Borowitz <dborowitz@google.com> 1489070943 -0500

Ensure constants are declared as immutable collections

This communicates important semantic guarantees to callers, as described
in the ImmutableCollection javadoc. It also makes calls to mutating
methods result in compiler warnings.

PiperOrigin-RevId: 148916986
Change-Id: I5a400daca8b7a339e9cd7298e1ed1f6db3c54bfc