'Returns a JSON-format summary of all the cached
exception reports'

def summary(self, environ, start_response):

    start_response('200    OK', [('Content-type', 'text/x-json')])
    data = []
    items = self.debug_infos.values()
    items.sort((lambda a, b: cmp(a.created, b.created)))
    data = [item.json() for item in items]
    return [repr(data)]
