/**
  * This function creates a single converter instance.
  *
  * @param ConverterDefinition $converterDefinition
  *
  * @throws InvalidConverterException
  * @return ConverterInterface
  */
 public static function createConverterInstance(ConverterDefinition $converterDefinition)
 {
     $class = $converterDefinition->getFullQualifiedClassName();
     if (!class_exists($class)) {
         $message = sprintf('The converter "%s" (%s) does not exist.', $converterDefinition->getClassName(), $class);
         throw new InvalidConverterException($message);
     }
     $parameters = $converterDefinition->getParameters();
     if ($parameters !== null) {
         return new $class($parameters);
     }
     return new $class();
 }