original_string: public function isMissing($option)
      {
          return isset($this->required[$option]) && !\array_key_exists($option, $this->defaults);
      }
code: public function isMissing($option)
      {
          return isset($this->required[$option]) && !\array_key_exists($option, $this->defaults);
      }
code_tokens: public function isMissing ( $ option ) { return isset ( $ this -> required [ $ option ] ) && ! \ array_key_exists ( $ option , $ this -> defaults ) ; }
docstring: Returns whether an option is missing a default value.
  
  An option is missing if it was passed to {@link setRequired()}, but not
  to {@link setDefault()}. This option must be passed explicitly to
  {@link resolve()}, otherwise an exception will be thrown.
  
  @param string $option The name of the option
  
  @return bool Whether the option is missing
docstring_tokens: Returns whether an option is missing a default value .