code: function findDeprecatedStylelintRules() {
    if (!argv.deprecated && !argv.unused) {
      return Promise.resolve();
    }
  
    const isDeprecatedPromises = _.map(rules.stylelintAll, isDDeprecated);
  
    return Promise.all(isDeprecatedPromises).then(rulesIsDeprecated => {
      rules.stylelintDeprecated = _.filter(
        rules.stylelintAll,
        (rule, index) => rulesIsDeprecated[index]
      );
  
      // Don't remove, just for testing deprecated rules matching
      if (argv.testDeprecated) {
        rules.stylelintDeprecated.push('color-hex-case', 'color-hex-length');
      }
  
      if (argv.unused) {
        rules.stylelintNoDeprecated = _.difference(rules.stylelintAll, rules.stylelintDeprecated);
      }
  
      return rules.stylelintDeprecated;
    });
  }
docs: Find all deprecated rules from the list of stylelint rules
  
  @returns {Promise}