+
+/**
+ * Removes the previously-installed pattern.
+ * You must call installPattern() before calling this. You can install at most
+ * one pattern at a time--there is no pattern stack.
+ */
+CanvasRenderingContext2D.prototype.uninstallPattern = function() {
+ // This will be replaced by a non-error version when a pattern is installed.
+ throw "Must install a line pattern before uninstalling it.";
+}