Implement getRootDatasetSequence for SequenceI

diff --git a/src/jalview/datamodel/SequenceI.java b/src/jalview/datamodel/SequenceI.java
index 8f1d160..d8a5462 100755 (executable)
--- a/src/jalview/datamodel/SequenceI.java
+++ b/src/jalview/datamodel/SequenceI.java
@@ -396,6 +396,19 @@ public interface SequenceI extends ASequenceI
   public SequenceI getDatasetSequence();
 
   /**
+   * Returns the top grandparent in the dataset sequences hierarchy.
+   */
+  public default SequenceI getRootDatasetSequence()
+  {
+    var sequence = this;
+    while (sequence.getDatasetSequence() != null)
+    {
+      sequence = sequence.getDatasetSequence();
+    }
+    return sequence;
+  }
+
+  /**
    * Returns a new array containing this sequence's annotations, or null.
    */
   public AlignmentAnnotation[] getAnnotation();