Help tagging a build

Hi,

I want to apply a tag to specific builds. I am able to get the IBuildResult handle but when I try to do setTags(), I get an exception:


IBuildResult buildResult = (IBuildResult) result;
if(buildResult.getLabel().equals("20111123-1018")) {
buildResult.setTags("steve-test");



Caused by: com.ibm.team.repository.common.internal.ImmutablePropertyException
at com.ibm.team.repository.common.internal.util.ItemUtil$ProtectAdapter.notifyChanged(ItemUtil.java:2026)
at org.eclipse.emf.common.notify.impl.BasicNotifierImpl.eNotify(BasicNotifierImpl.java:380)
at com.ibm.team.build.internal.common.model.impl.BuildResultImpl.setTags(BuildResultImpl.java:1021)



Is there a different way I should be doing this?

Thanks,

-Steve