src/Type/SchemaValidationContext.php
private function getImplementsInterfaceNode(ObjectType $type, $iface)
    {
        $nodes = $this->getAllImplementsInterfaceNodes($type, $iface);

        return $nodes[0] ?? null;
    }
private function getImplementsInterfaceNode(ObjectType $type, $iface)
    {
        $nodes = $this->getAllImplementsInterfaceNodes($type, $iface);

        return $nodes[0] ?? null;
    }
@param InterfaceType $iface

@return NamedTypeNode|null