docs: function body (req, res, record, model, cb) {
  
      var overview = model.linz.formtools.overview;
  
      if (typeof overview.body === 'function') {
  
          // return a string of HTML content
          return overview.body(req, res, record, model, cb);
  
      }
  
      // Since overview.body is not a function, than it must be an Array.
      async.mapSeries(overview.body, function (section, callback) {
  
          // Skip if the section is an array or function.
          const requiresLabel = !Array.isArray(section) && typeof section !== 'function';
  
          // each section object in overview body DSL must have label.
          if (requiresLabel && !section.label) {
              return cb(new Error('One of the label is missing in overview of ' + model.modelName + ' model.'));
          }
  
          // returns an array of objects
          return getSections(req, res, record, model, section, true, callback);
  
      }, cb);
  
  }