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.";
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.";