Adding isNotEmpty property to collection and string.

BUG= http://dartbug.com/3074
R=floitsch@google.com

Review URL: https://codereview.chromium.org//15263004

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart/pkg/yaml@23294 260f80e4-7a28-3924-810f-c04153c831b5
1 file changed
tree: cdc16e5ea912e5eb8948b4d18269cbe890e6d3af
  1. pkgs/