src/Utils/SchemaPrinter.php
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';
    }
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';
    }
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.