code: 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);
    }
docs: Create a joi object that can validate a `map` for Cassandra.
  
  @param {(String|Joi)} keyType - used for validating the fields of the object, ignored currently
  @param {Joi} valueType - used for validating the values of the fields in the object
  @returns {Joi} - the validator