/** The key of the configuration. e.g. label */
    String INDEX_FIELD_LABEL = "index.field.label";

    /** The key of the configuration. e.g. mimetype */
    String INDEX_FIELD_MIMETYPE = "index.field.mimetype";

    /** The key of the configuration. e.g. parent_id */
    String INDEX_FIELD_parent_id = "index.field.parent_id";

    /** The key of the configuration. e.g. important_content */