final OtpErlangObject res = backend.call(ERLIDE_OPEN,
"get_external_module_tree", "x",
mkContext(externalModules, null, pathVars, null, null));
if (Util.isOk(res)) {
OtpErlangTuple t = (OtpErlangTuple) res;
final OtpErlangList l = (OtpErlangList) t.elementAt(1);
final List<ExternalTreeEntry> result = Lists.newArrayListWithCapacity(l
.arity());
for (final OtpErlangObject i : l) {
t = (OtpErlangTuple) i;
final String parentPath = Util.stringValue(t.elementAt(0));
final String path = Util.stringValue(t.elementAt(1));