code: public <V> Callable<V,IOException> asCallableWith(final FileCallable<V> task) {
          return new CallableWith<>(task);
      }
docs: Takes a {@link FilePath}+{@link FileCallable} pair and returns the equivalent {@link Callable}.
  When executing the resulting {@link Callable}, it executes {@link FileCallable#act(FileCallable)}
  on this {@link FilePath}.
  
  @since 1.522