def METHOD_NAME(self, view, prefix, locations):
    settings = sublime.load_settings('CSS.sublime-settings')
    if settings.get('disable_default_completions'):
        return None
    selector = settings.get('default_completions_selector', '')
    if isinstance(selector, list):
        selector = ''.join(selector)
    pt = locations[0]
    if not match_selector(view, pt, selector):
        return None
    if match_selector(view, pt, "meta.property-value.css meta.function-call.arguments"):
        items = self.complete_function_argument(view, prefix, pt)
    elif view.match_selector(pt - 1, "meta.property-value.css, punctuation.separator.key-value"):
        items = self.complete_property_value(view, prefix, pt)
    elif view.match_selector(pt - 1, "meta.property-name.css, meta.property-list.css - meta.selector"):
        items = self.complete_property_name(view, prefix, pt)
    else:
        # TODO: provide selectors, at-rules
        items = None
    if items:
        return sublime.CompletionList(items, sublime.INHIBIT_WORD_COMPLETIONS)
    return None