* from 1), or null if no residues are included in the range
*
* @param fromColum
- * - first column base 1
+ * - first column base 1. (0 and negative positions are rounded up)
* @param toColumn
* - last column, base 1
- * @return
+ * @return null if fromColum>toColumn
*/
public ContiguousI findPositions(int fromColum, int toColumn);