Convert the first argument to optional to match the underlying API.
See and
@@ -415,12 +415,12 @@ function SharedArrayBuffer(length) {}
SharedArrayBuffer.prototype.byteLength;
/**
- * @param {number} begin
+ * @param {number=} opt_begin
* @param {number=} opt_end
* @return {!SharedArrayBuffer}
* @nosideeffects
*/
-SharedArrayBuffer.prototype.slice = function(begin, opt_end) {};
+SharedArrayBuffer.prototype.slice = function(opt_begin, opt_end) {};
/**
