lib/workflow-in-memory-backend.js
function getRunners(callback) {
            var theRunners = {};

            Object.keys(runners).forEach(function (uuid) {
                theRunners[uuid] = runners[uuid].active_at;
            });

            return callback(null, theRunners);
        }
function getRunners(callback) {
            var theRunners = {};

            Object.keys(runners).forEach(function (uuid) {
                theRunners[uuid] = runners[uuid].active_at;
            });

            return callback(null, theRunners);
        }
Get all the registered runners: - callback - f(err, runners)