code: public function fieldLength($field, bool $serialized = true): int
      {
          if ($serialized) {
              return $this->redis->hstrlen($this->key, $field);
          }
  
          $val = $this->get($field);
          if ($val === null) {
              return 0;
          }
  
          return \strlen($val);
      }
docs: @param int|string $field                              Selected field that will be measured.
  @param bool       $serialized                         True: Measure the internal serialized string.
  False: Unserialize the value and then measure.
  Note: Zero will be returned upon non-existent field or key.
  
  @return int Length of content in $field.