code: private static function isSchemaOfCommonNames(Schema $schema)
      {
          $queryType = $schema->getQueryType();
          if ($queryType && $queryType->name !== 'Query') {
              return false;
          }
  
          $mutationType = $schema->getMutationType();
          if ($mutationType && $mutationType->name !== 'Mutation') {
              return false;
          }
  
          $subscriptionType = $schema->getSubscriptionType();
  
          return ! $subscriptionType || $subscriptionType->name === 'Subscription';
      }
docs: GraphQL schema define root types for each type of operation. These types are
  the same as any other type and can be named in any manner, however there is
  a common naming convention:
  
  schema {
  query: Query
  mutation: Mutation
  }
  
  When using this naming convention, the schema description can be omitted.