+ */
+
+/* Implementation notes:
+ *
+ * Methods which change the hiddenColumns collection should use a writeLock to
+ * prevent other threads accessing the hiddenColumns collection while changes
+ * are being made. They should also reset the hidden columns cursor, and either
+ * update the hidden columns count, or set it to 0 (so that it will later be
+ * updated when needed).
+ *
+ *
+ * Methods which only need read access to the hidden columns collection should
+ * use a readLock to prevent other threads changing the hidden columns
+ * collection while it is in use.