p.setAssignedLabel(hudson.getLabel("!win"));
FreeStyleBuild b = assertBuildStatusSuccess(p.scheduleBuild2(0));
assertSame(hudson,b.getBuiltOn());
p.setAssignedLabel(hudson.getLabel("win"));
b = assertBuildStatusSuccess(p.scheduleBuild2(0));
assertSame(s,b.getBuiltOn());
p.setAssignedLabel(hudson.getLabel("!win"));
b = assertBuildStatusSuccess(p.scheduleBuild2(0));
assertSame(hudson,b.getBuiltOn());