diff --git a/src/cpl_query/__init__.py b/src/cpl_query/__init__.py
index 843037d4..c3c0020a 100644
--- a/src/cpl_query/__init__.py
+++ b/src/cpl_query/__init__.py
@@ -15,11 +15,11 @@ __title__ = 'cpl_query'
 __author__ = 'Sven Heidemann'
 __license__ = 'MIT'
 __copyright__ = 'Copyright (c) 2020 - 2021 sh-edraft.de'
-__version__ = '2021.11.0.post1'
+__version__ = '2021.11.0.post2'
 
 from collections import namedtuple
 
 # imports: 
 
 VersionInfo = namedtuple('VersionInfo', 'major minor micro')
-version_info = VersionInfo(major='2021', minor='11', micro='0.post1')
+version_info = VersionInfo(major='2021', minor='11', micro='0.post2')
diff --git a/src/cpl_query/_query/__init__.py b/src/cpl_query/_query/__init__.py
index f5b4620e..dbdb0c88 100644
--- a/src/cpl_query/_query/__init__.py
+++ b/src/cpl_query/_query/__init__.py
@@ -15,11 +15,11 @@ __title__ = 'cpl_query._query'
 __author__ = 'Sven Heidemann'
 __license__ = 'MIT'
 __copyright__ = 'Copyright (c) 2020 - 2021 sh-edraft.de'
-__version__ = '2021.11.0.post1'
+__version__ = '2021.11.0.post2'
 
 from collections import namedtuple
 
 # imports:
 
 VersionInfo = namedtuple('VersionInfo', 'major minor micro')
-version_info = VersionInfo(major='2021', minor='11', micro='0.post1')
+version_info = VersionInfo(major='2021', minor='11', micro='0.post2')
diff --git a/src/cpl_query/cpl_query.json b/src/cpl_query/cpl_query.json
index 5dbc1b30..3484e395 100644
--- a/src/cpl_query/cpl_query.json
+++ b/src/cpl_query/cpl_query.json
@@ -4,7 +4,7 @@
     "Version": {
       "Major": "2021",
       "Minor": "11",
-      "Micro": "0.post1"
+      "Micro": "0.post2"
     },
     "Author": "Sven Heidemann",
     "AuthorEmail": "sven.heidemann@sh-edraft.de",
diff --git a/src/cpl_query/extension/__init__.py b/src/cpl_query/extension/__init__.py
index 7da75457..f09b1bb5 100644
--- a/src/cpl_query/extension/__init__.py
+++ b/src/cpl_query/extension/__init__.py
@@ -15,7 +15,7 @@ __title__ = 'cpl_query.extension'
 __author__ = 'Sven Heidemann'
 __license__ = 'MIT'
 __copyright__ = 'Copyright (c) 2020 - 2021 sh-edraft.de'
-__version__ = '2021.11.0.post1'
+__version__ = '2021.11.0.post2'
 
 from collections import namedtuple
 
@@ -27,4 +27,4 @@ from .ordered_iterable_abc import OrderedIterableABC
 from .ordered_iterable import OrderedIterable
 
 VersionInfo = namedtuple('VersionInfo', 'major minor micro')
-version_info = VersionInfo(major='2021', minor='11', micro='0.post1')
+version_info = VersionInfo(major='2021', minor='11', micro='0.post2')
diff --git a/src/cpl_query/extension/iterable_abc.py b/src/cpl_query/extension/iterable_abc.py
index e04a4ce5..24a4a13f 100644
--- a/src/cpl_query/extension/iterable_abc.py
+++ b/src/cpl_query/extension/iterable_abc.py
@@ -100,7 +100,7 @@ class IterableABC(ABC, list):
         pass
 
     @abstractmethod
-    def count(self, func: Callable) -> int:
+    def count(self, func: Callable = None) -> int:
         r"""Returns length of list or count of found elements
 
         Parameter
@@ -115,7 +115,7 @@ class IterableABC(ABC, list):
         pass
 
     @abstractmethod
-    def distinct(self, func: Callable) -> 'IterableABC':
+    def distinct(self, func: Callable = None) -> 'IterableABC':
         r"""Returns list without redundancies
 
         Parameter