+ * Returns the range of sequence positions included in the given alignment
+ * position range. If no positions are included (the range is entirely gaps),
+ * then returns null.
+ *
+ * <pre>
+ * Example:
+ * >Seq/8-13
+ * ABC--DE-F
+ * findPositions(1, 4) returns Range(9, 9) // B only
+ * findPositions(3, 4) returns null // all gaps
+ * findPositions(2, 6) returns Range(10, 12) // CDE
+ * findPositions(3, 7) returns Range(11,12) // DE
+ * </pre>
+ *
+ * @param fromCol
+ * first aligned column position (base 0, inclusive)
+ * @param toCol
+ * last aligned column position (base 0, inclusive)
+ *
+ * @return
+ */
+ public Range findPositions(int fromCol, int toCol);
+
+ /**