docs: function customFn (code, description) {
      if (typeof code !== 'string') {
          throw new Error(`Inline code '${description}' has empty code`);
      }
      let resolver;
  
      try {
          resolver = eval(code); // eslint-disable-line
      } catch (e) {
          throw new Error(`Invalid inline code '${description}': ${e.message}`);
      }
  
      if (typeof resolver !== 'function') {
          throw new Error(`Invalid inline code '${description}': must be a function`);
      }
  
      return resolver;
  }