def tag(self, text):
        """Retrieves list of keywords in text.

        Parameters
        ----------
        text: Text
            The text to search for events.

        Returns
        -------
        list of vents sorted by start, end
        """
        if self.search_method == 'ahocorasick':
            events = self._find_keywords_ahocorasick(text.text)
        elif self.search_method == 'naive':
            events = self._find_keywords_naive(text.text)

        events = self._resolve_conflicts(events)
        if self.mapping:
            for item in events:
                item['type'] = self.map[
                    text.text[item['start']:item['end']]
                ]

        if self.return_layer:
            return events
        else:
            text[self.layer_name] = events