code: public List<? extends VecPaired<Vec, Double>> searchR(Vec q)
      {
          return searchR(q, false);
      }
docs: Performs a search for points within the set {@link #getRadius() radius}
  of the query point.
  @param q the query point to search near
  @return a list of vectors paired with their true distance from the query
  point that are within the desired radius of the query point