code: @SafeVarargs
    public static <T> T firstSuccess(FuncE0<T, ?>... tasks) throws IllegalStateException {
      for (FuncE0<T, ?> task : tasks) {
        Either<T, ?> res = throwToReturn(task);
        if (res.isLeft()) {
          return res.getLeft();
        }
      }
      throw new IllegalStateException("All tasks failed");
    }
docs: Return the first result of these tasks<br>
  IGNORE EXCEPTIONS.
  
  @param tasks
  @return can be null
  @throws IllegalStateException If all tasks failed.