docs: function (keyType, valueType) {
      var meta = findMeta(valueType);
      return joi.object().meta({
        cql: true,
        type: 'map',
        mapType: ['text', meta.type],
        serialize: convertMap(meta.serialize),
        deserialize: convertMap(meta.deserialize)
      }).pattern(/[\-\w]+/, valueType);
    }