final List<IErlElement> externals = project
.getChildrenOfKind(ErlElementKind.EXTERNAL_ROOT);
final IErlExternal external = (IErlExternal) externals.get(0);
external.open(null);
final IErlExternal externalOTP = (IErlExternal) externals.get(1);
externalOTP.open(null);
final IErlExternal externalDialyzer = (IErlExternal) externalOTP
.getChildNamed("dialyzer");
assertTrue(external.hasIncludes());
assertTrue(externalOTP.hasIncludes());
assertFalse(externalDialyzer.hasIncludes());