code: public static FileSystem getOptionallyThrottledFileSystem(FileSystem fs, State state) throws IOException {
      DeprecationUtils.renameDeprecatedKeys(state, MAX_FILESYSTEM_QPS, DEPRECATED_KEYS);
  
      if (state.contains(MAX_FILESYSTEM_QPS)) {
        return getOptionallyThrottledFileSystem(fs, state.getPropAsInt(MAX_FILESYSTEM_QPS));
      }
      return fs;
    }
docs: Calls {@link #getOptionallyThrottledFileSystem(FileSystem, int)} parsing the qps from the input {@link State}
  at key {@link #MAX_FILESYSTEM_QPS}.
  @throws IOException