Collection<XmlFile> (@NotNull String namespace, @NotNull Project project, @Nullable Module module) { final List<IndexedRelevantResource<String, XsdNamespaceBuilder>> resources = XmlNamespaceIndex.getResourcesByNamespace(namespace, project, module); final PsiManager psiManager = PsiManager.getInstance(project); return ContainerUtil.mapNotNull(resources, (NullableFunction<IndexedRelevantResource<String, XsdNamespaceBuilder>, XmlFile>)resource -> { PsiFile file = psiManager.findFile(resource.getFile()); return file instanceof XmlFile ? (XmlFile)file : null; }); }