code: public function setValue($value)
      {
          $this->value = number_format($value, 6, '.', '');
  
          if (strlen((string)$this->value) > 19) {
              throw new \Exception('Value too long');
          }
  
          return $this;
      }
docs: @param $value
  
  @throws \Exception
  
  @return $this