whole_func_string: function isRunnerIdle(runner_id, callback) {
              if (!runners[runner_id] || (runners[runner_id].idle === true)) {
                  return callback(true);
              } else {
                  return callback(false);
              }
          }
func_code_string: function isRunnerIdle(runner_id, callback) {
              if (!runners[runner_id] || (runners[runner_id].idle === true)) {
                  return callback(true);
              } else {
                  return callback(false);
              }
          }
func_documentation_string: Check if the given runner is idle - runner_id - String, unique identifier for runner - callback - f(boolean)