code: public Query startAfter(Object... fieldValues) {
      QueryOptions newOptions = new QueryOptions(options);
      newOptions.startCursor = createCursor(newOptions.fieldOrders, fieldValues, false);
      return new Query(firestore, path, newOptions);
    }
docs: Creates and returns a new Query that starts after the provided fields relative to the order of
  the query. The order of the field values must match the order of the order by clauses of the
  query.
  
  @param fieldValues The field values to start this query after, in order of the query's order
  by.
  @return The created Query.