addonCommands() {
    const Command = require('../models/command');
    let commands = Object.create(null);
    this.addons.forEach((addon) => {
      if (!addon.includedCommands) {
        return;
      }

      let token = heimdall.start({
        name: `lookup-commands: ${addon.name}`,
        addonName: addon.name,
        addonCommandInitialization: true,
      });

      let includedCommands = addon.includedCommands();
      let addonCommands = Object.create(null);

      for (let key in includedCommands) {
        if (typeof includedCommands[key] === 'function') {
          addonCommands[key] = includedCommands[key];
        } else {
          addonCommands[key] = Command.extend(includedCommands[key]);
        }
      }
      if (Object.keys(addonCommands).length) {
        commands[addon.name] = addonCommands;
      }

      token.stop();
    });
    return commands;
  }
Returns what commands are made available by addons by inspecting
    `includedCommands` for every addon.

    @private
    @method addonCommands
    @return {Object} Addon names and command maps as key-value pairs