code: function kill(pid, signal) {
    signal = _.isUndefined(signal) ? 'SIGINT' : signal;
    // process.kill does not recognize many of the well known numeric signals,
    // only by name
    if (_.isFinite(signal) && _.has(signalsMap, signal)) {
      signal = signalsMap[signal];
    }
  
    if (!_.isFinite(pid)) return false;
    try {
      process.kill(pid, signal);
    } catch (e) {
      return false;
    }
    return true;
  }
docs: Send signal to process
  @function $os~kill
  @param {number} pid - Process ID
  @param {number|string} [signal=SIGINT] - Signal number or name
  @returns {boolean} - True if it successed to kill the process
  @example
  // Send 'SIGKILL' signal to process 123213
  $os.kill(123213, 'SIGKILL')
  // => true