DI\Debug::dumpDefinition PHP Method

    public static function dumpDefinition(Definition $definition)
    {
        return (string) $definition;
    }

 /**
  * {@inheritdoc}
  */
 public function dump(Definition $definition)
 {
     if (!$definition instanceof EnvironmentVariableDefinition) {
         throw new \InvalidArgumentException(sprintf('This definition dumper is only compatible with EnvironmentVariableDefinition objects, %s given', get_class($definition)));
     }
     $str = '    variable = ' . $definition->getVariableName();
     $str .= PHP_EOL . '    optional = ' . ($definition->isOptional() ? 'yes' : 'no');
     if ($definition->isOptional()) {
         $defaultValue = $definition->getDefaultValue();
         if ($defaultValue instanceof DefinitionHelper) {
             $nestedDefinition = Debug::dumpDefinition($defaultValue->getDefinition(''));
             $defaultValueStr = $this->indent($nestedDefinition);
         } else {
             $defaultValueStr = var_export($defaultValue, true);
         }
         $str .= PHP_EOL . '    default = ' . $defaultValueStr;
     }
     return sprintf('Environment variable (' . PHP_EOL . '%s' . PHP_EOL . ')', $str);
 }