diff --git a/mockfirestore/collection.py b/mockfirestore/collection.py
index 431c074..0b3f9d7 100644
--- a/mockfirestore/collection.py
+++ b/mockfirestore/collection.py
@@ -14,6 +14,10 @@ def __init__(self, data: Store, path: List[str],
         self._path = path
         self.parent = parent
 
+    @property
+    def id(self):
+        return self._path[-1]
+
     def document(self, document_id: Optional[str] = None) -> DocumentReference:
         collection = get_by_path(self._data, self._path)
         if document_id is None:
diff --git a/mockfirestore/document.py b/mockfirestore/document.py
index 24aa433..edb0f5f 100644
--- a/mockfirestore/document.py
+++ b/mockfirestore/document.py
@@ -63,7 +63,11 @@ def __init__(self, data: Store, path: List[str],
     def id(self):
         return self._path[-1]
 
-    def get(self) -> DocumentSnapshot:
+    @property
+    def path(self):
+        return '/'.join(self._path)
+
+    def get(self, **kwargs) -> DocumentSnapshot:
         return DocumentSnapshot(self, get_by_path(self._data, self._path))
 
     def delete(self):
@@ -92,3 +96,13 @@ def collection(self, name) -> 'CollectionReference':
         if name not in document:
             set_by_path(self._data, new_path, {})
         return CollectionReference(self._data, new_path, parent=self)
+
+    def collections(self) -> list['CollectionReference']:
+        from mockfirestore.collection import CollectionReference
+        document = get_by_path(self._data, self._path)
+        _collections = []
+        for collname, values in document.items():
+            if isinstance(values, dict):
+                new_path = self._path + [collname]
+                _collections.append(CollectionReference(self._data, new_path, parent=self))
+        return _collections
diff --git a/tests/test_document_reference.py b/tests/test_document_reference.py
index c582b36..4cc5310 100644
--- a/tests/test_document_reference.py
+++ b/tests/test_document_reference.py
@@ -16,6 +16,23 @@ def test_get_document_by_path(self):
         self.assertEqual({'id': 1}, doc.to_dict())
         self.assertEqual('first', doc.id)
 
+    def test_get_document_by_path_with_transaction_kwarg(self):
+        fs = MockFirestore()
+        fs._data = {'foo': {
+            'first': {'id': 1}
+        }}
+        doc = fs.document('foo/first').get(transaction='tx')
+        self.assertEqual({'id': 1}, doc.to_dict())
+        self.assertEqual('first', doc.id)
+
+    def test_document_path_property(self):
+        fs = MockFirestore()
+        fs._data = {'foo': {
+            'first': {'id': 1}
+        }}
+        doc = fs.document('foo/first')
+        self.assertEqual('foo/first', doc.path)
+
     def test_set_document_by_path(self):
         fs = MockFirestore()
         fs._data = {}
@@ -23,7 +40,7 @@ def test_set_document_by_path(self):
         fs.document('foo/doc1/bar/doc2').set(doc_content)
         doc = fs.document('foo/doc1/bar/doc2').get().to_dict()
         self.assertEqual(doc_content, doc)
-        
+
     def test_document_get_returnsDocument(self):
         fs = MockFirestore()
         fs._data = {'foo': {
@@ -72,6 +89,23 @@ def test_get_nestedDocument(self):
 
         self.assertEqual({'id': 1.1}, doc)
 
+    def test_get_nestedCollections(self):
+        fs = MockFirestore()
+        fs._data = {'top_collection': {
+            'top_document': {
+                'id': 1,
+                'nested_collection': {
+                    'nested_document': {'id': 1.1}
+                }
+            }
+        }}
+        collections = fs.collection('top_collection')\
+            .document('top_document')\
+            .collections()
+
+        self.assertEqual(1, len(collections))
+        self.assertEqual(collections[0].id, 'nested_collection')
+
     def test_get_nestedDocument_documentDoesNotExist(self):
         fs = MockFirestore()
         fs._data = {'top_collection': {