+ /**
+ * Sort sequences by feature score or density, optionally restricted by
+ * feature types, feature groups, or alignment start/end positions.
+ * <p>
+ * If the sort is repeated for the same combination of types and groups, sort
+ * order is reversed.
+ *
+ * @param featureLabels
+ * a list of feature types to include (or null for all)
+ * @param groupLabels
+ * a list of feature groups to include (or null for all)
+ * @param start
+ * start column position to include (base zero)
+ * @param stop
+ * end column position to include (base zero)
+ * @param alignment
+ * the alignment to be sorted
+ * @param method
+ * either "average_score" or "density" ("text" not yet implemented)
+ */