code: public List<Group> getGroupList(final int[] priKeyIndices, final int numStdDev,
        final int limit) {
      //allows subsequent queries with different priKeyIndices without rebuilding the map
      if (!mapValid) { populateMap(priKeyIndices); }
      return populateList(numStdDev, limit);
    }
docs: Return the most frequent Groups associated with Primary Keys based on the size of the groups.
  @param priKeyIndices the indices of the primary dimensions
  @param numStdDev the number of standard deviations for the error bounds, this value is an
  integer and must be one of 1, 2, or 3.
  <a href="{@docRoot}/resources/dictionary.html#numStdDev">See Number of Standard Deviations</a>
  @param limit the maximum number of rows to return. If &le; 0, all rows will be returned.
  @return the most frequent Groups associated with Primary Keys based on the size of the groups.