PoiCategoriesQuery is an interface designed to transfer SearchAPI parameters in a readable manner by implementing class: PoiCategoriesQueryBuilder. The PoiCategoriesQuery instance can be constructed using the associated PoiCategoriesQueryBuilder class. Once constructed, the user cannot change the field values.
Language in which the poi categories should be returned. Should be one of supported IETF language tags. When language is not specified english is used as a default.