- * Calls the Ensembl lookup REST endpoint and retrieves the 'Parent' for the
- * given identifier, or null if not found
+ * Calls the Ensembl lookup REST endpoint and returns
+ * <ul>
+ * <li>the 'id' for the identifier if its type is "Gene"</li>
+ * <li>the 'Parent' if its type is 'Transcript'</li>
+ * <ul>
+ * If the type is 'Translation', does a recursive call to this method, passing
+ * in the 'Parent' (transcript id).