assignOption(option, parsedOptions, commandOptions) {
    let isValid = isValidParsedOption(option, parsedOptions[option.name]);
    if (isValid) {
      if (parsedOptions[option.name] === undefined) {
        if (option.default !== undefined) {
          commandOptions[option.key] = option.default;
        }

        if (this.settings[option.name] !== undefined) {
          commandOptions[option.key] = this.settings[option.name];
        } else if (this.settings[option.key] !== undefined) {
          commandOptions[option.key] = this.settings[option.key];
        }
      } else {
        commandOptions[option.key] = parsedOptions[option.name];
        delete parsedOptions[option.name];
      }
    } else {
      this.ui.writeLine(
        `The specified command ${chalk.green(this.name)} requires the option ${chalk.green(option.name)}.`
      );
    }
    return isValid;
  }
Assigns option
    @method assignOption
    @param {Object} option
    @param {Object} parsedOptions
    @param {Object} commandOptions
    @return {Boolean}