code: function inquire(moduleName) {
      try {
          var mod = eval("quire".replace(/^/,"re"))(moduleName); // eslint-disable-line no-eval
          if (mod && (mod.length || Object.keys(mod).length))
              return mod;
      } catch (e) {} // eslint-disable-line no-empty
      return null;
  }
docs: Requires a module only if available.
  @memberof util
  @param {string} moduleName Module to require
  @returns {?Object} Required module if available and not empty, otherwise `null`