def _add_extensions(self, extensions):
        grouped = defaultdict(set)
        for extension in extensions:
            ext_id = extension.qualified_id
            if ext_id in self._extensions:
                msg = "extension '%s' is already registered"
                raise ValueError(msg % ext_id)
            self._extensions[ext_id] = extension
            grouped[extension.point].add(extension)

        for point_id, exts in grouped.iteritems():
            self._contributions[point_id].update(exts)
            if point_id in self._extension_points:
                point = self._extension_points[point_id]
                self._update_extension_point(point, (), exts)
Add extensions to the workbench.
dataset/ETHPy150Open nucleic/enaml/enaml/workbench/workbench.py/Workbench._add_extensions