Add nullable_positive_or_zero_int.py

#18

Author: n1nj4t4nuk1

pyvalueobjects/numbers/nullable_positive_or_zero_int.py

@@ -0,0 +1,10 @@
+from pyvalueobjects.abstract.nullablevalueobject import build_nullable
+from pyvalueobjects.numbers.positive_or_zero_int import PositiveOrZeroInt
+
+_nullable_cls = build_nullable(PositiveOrZeroInt)
+
+
+class NullablePositiveOrZeroInt(_nullable_cls):
+
+    def __init__(self, value: int = None):
+        super().__init__(value)