whole_func_string: function cancelJob(uuid, cb) {
              if (typeof (uuid) === 'undefined') {
                  return cb(new e.BackendInternalError(
                    'cancelJob uuid(String) required'));
              }
  
              jobs[uuid].execution = 'canceled';
              delete jobs[uuid].runner_id;
              if (typeof (jobs[uuid].locks) !== 'undefined') {
                  delete locked_targets[uuid];
              }
              return cb(null, jobs[uuid]);
          }
func_code_string: function cancelJob(uuid, cb) {
              if (typeof (uuid) === 'undefined') {
                  return cb(new e.BackendInternalError(
                    'cancelJob uuid(String) required'));
              }
  
              jobs[uuid].execution = 'canceled';
              delete jobs[uuid].runner_id;
              if (typeof (jobs[uuid].locks) !== 'undefined') {
                  delete locked_targets[uuid];
              }
              return cb(null, jobs[uuid]);
          }
func_documentation_string: Unlock the job, mark it as canceled, and remove the runner_id uuid - string, the job uuid. cb - f(err, job) callback will be called with error if something fails, otherwise it'll return the updated job using getJob.