original_string: protected function getConfigOption(array $config, $key)
      {
          if (empty($config[$key]) || !is_string($config[$key])) {
              throw new \DomainException(
                  "$key must be a non-empty string"
              );
          }
          return $config[$key];
      }
code: protected function getConfigOption(array $config, $key)
      {
          if (empty($config[$key]) || !is_string($config[$key])) {
              throw new \DomainException(
                  "$key must be a non-empty string"
              );
          }
          return $config[$key];
      }
code_tokens: protected function getConfigOption ( array $ config , $ key ) { if ( empty ( $ config [ $ key ] ) || ! is_string ( $ config [ $ key ] ) ) { throw new \ DomainException ( "$key must be a non-empty string" ) ; } return $ config [ $ key ] ; }
docstring: Extracts a string from the config options map.
  
  @param array $config
  @param string $key
  @return string
  @throws \DomainException if password is unspecified or not a string
docstring_tokens: Extracts a string from the config options map .