docs: function(columnOrIndex) {
          var name, index, result;
  
          if (typeof columnOrIndex === 'number') {
              index = columnOrIndex;
              name = this.schema[index].name;
          } else {
              name = columnOrIndex;
              index = this.schema.findIndex(function(columnSchema) {
                  return columnSchema.name === name;
              });
          }
  
          if (name && index >= 0) {
              result = {
                  name: name,
                  index: index
              };
          }
  
          return result;
      }