@Override
public void getProposals(AceEditor editor, AceEditorCursorPosition pos, String prefix, AceCompletionCallback callback) {
GWT.log("sending completion proposals");
callback.invokeWithCompletions(new AceCompletion[]{
new AceCompletionValue("first", "firstcompletion", "custom", 10),
new AceCompletionValue("second", "secondcompletion", "custom", 11),
new AceCompletionValue("third", "thirdcompletion", "custom", 12),
new AceCompletionSnippet("fourth (snippets)",
new AceCompletionSnippetSegment[]{
new AceCompletionSnippetSegmentLiteral("filler_"),
new AceCompletionSnippetSegmentTabstopItem("tabstop1"),
new AceCompletionSnippetSegmentLiteral("_\\filler_"), // putting backslash in here to prove escaping is working