private IDictionary DoImport()

in resharper/resharper-unity/src/Unity/Yaml/Psi/DeferredCaches/PrefabImportCache.cs [123:199]
63 lines of code
16 McCabe index (conditional complexity)

        private IDictionary<long, IHierarchyElement> DoImport(Guid ownerGuid, AssetDocumentHierarchyElement assetDocumentHierarchyElement, HashSet<Guid> visitedGuid)
        {
            var result = new Dictionary<long, IHierarchyElement>();
            foreach (var prefabInstanceHierarchy in assetDocumentHierarchyElement.GetPrefabInstanceHierarchies())
            {
                Interruption.Current.CheckAndThrow();

                var guid = prefabInstanceHierarchy.SourcePrefabGuid;
                var sourceFilePath = myMetaFileGuidCache.GetAssetFilePathsFromGuid(guid).FirstOrDefault();
                if (sourceFilePath == null)
                    continue;
                if (!myUnityExternalFilesPsiModule.TryGetFileByPath(sourceFilePath, out var sourceFile))
                    continue;

                var prefabHierarchy = assetDocumentHierarchyElement.AssetDocumentHierarchyElementContainer.GetAssetHierarchyFor(sourceFile);
                if (prefabHierarchy == null)
                    continue;

                if (!myCache.TryGetFromCache(guid, out var importedElements))
                {
                    if (!visitedGuid.Contains(guid)) // invalid assets with cycles in prefab imports
                    {
                        myDependencies.Add(guid, ownerGuid);
                        visitedGuid.Add(guid);
                        importedElements = DoImport(guid, prefabHierarchy, visitedGuid);
                        StoreResult(guid, importedElements);
                    }
                    else
                    {
                        importedElements = EmptyDictionary<long, IHierarchyElement>.Instance;
                    }
                }

                foreach (var element in prefabHierarchy.Elements())
                {
                    if (element is IStrippedHierarchyElement)
                        continue;

                    if (element is IPrefabInstanceHierarchy)
                        continue;

                    var imported = element.Import(prefabInstanceHierarchy);
                    if (imported == null)
                        continue;
                    result[imported.Location.LocalDocumentAnchor] = imported;
                }

                foreach (var element in importedElements.Values)
                {
                    Assertion.Assert(!(element is IStrippedHierarchyElement), "element should be imported");
                    Assertion.Assert(!(element is IPrefabInstanceHierarchy), "prefab should be imported");

                    var imported = element.Import(prefabInstanceHierarchy);
                    if (imported == null)
                        continue;

                    result[imported.Location.LocalDocumentAnchor] = imported;
                }
            }

            foreach (var value in result.Values)
            {
                var transform = value as ImportedTransformHierarchy;
                var reference = transform?.OwningGameObject;
                if (reference == null)
                    continue;

                var importedGameObject = result.GetValueSafe(reference.Value.LocalDocumentAnchor) as ImportedGameObjectHierarchy;
                if (importedGameObject == null)
                    continue;

                importedGameObject.TransformHierarchy = transform;

            }

            return result;
        }