code: public function hasFlag($name)
      {
          $option = $this->definition->getOption($name);
  
          if (!$option->isFlag()) {
              throw new \InvalidArgumentException(sprintf('The "--%s" option is not a flag.', $name));
          }
  
          return !empty($this->options[$name]);
      }
docs: Returns true if flag is enabled and not empty.
  
  @param string $name
  Option name.
  
  @return boolean
  True if the flag is contained in raw parameters and its value is not
  empty.