Increase the number of shards of optimizer test.
The time cost is not at the boundary of medium due to various low-level changes.
@@ -39,7 +39,7 @@ distribute_py_test(
name = "optimizer_test",
size = "medium",
srcs = ["optimizer_test.py"],
- shard_count = 8,
+ shard_count = 16,
tags = [
"multi_gpu",
"no_windows",
