code: public function offsetSet($offset, $value): void
      {
          if ($offset === null) {
              $keys           = $this->keys();
              $biggestNumeric = -1;
              foreach ($keys as $key) {
                  if (\is_numeric($key) && \is_int($key + 0) && $key + 0 > $biggestNumeric) {
                      $biggestNumeric = $key + 0;
                  }
              }
              $offset = $biggestNumeric + 1;
          }
          $this->set($offset, $value);
      }
docs: "RedisHash[] =" is __NOT__ allowed! An offset always has to be there.
  {@inheritDoc}
  
  @throws \TypeError