Fix Incompatible types in assignment

monai/transforms/intensity/dictionary.py:334: error: Incompatible types in assignment
  (expression has type "Union[Tuple[Any, ...], List[Any]]", variable has type "Tuple[float, Any]")

Author: hjmjohnson

monai/transforms/intensity/dictionary.py

@@ -15,7 +15,7 @@
 Class names are ended with 'd' to denote dictionary-based transforms.
 """
 
-from typing import Union, Optional
+from typing import Union, Optional, Tuple
 
 import numpy as np
 
@@ -324,13 +324,15 @@ class RandAdjustContrastd(Randomizable, MapTransform):
             If single number, value is picked from (0.5, gamma), default is (0.5, 4.5).
     """
 
-    def __init__(self, keys: KeysCollection, prob=0.1, gamma=(0.5, 4.5)):
+    def __init__(self, keys: KeysCollection, prob=0.1, gamma: Union[Tuple[float, float], float] = (0.5, 4.5)):
         super().__init__(keys)
         self.prob = prob
+        self.gamma: Tuple[float, float]
         if not isinstance(gamma, (tuple, list)):
             assert gamma > 0.5, "if gamma is single number, must greater than 0.5 and value is picked from (0.5, gamma)"
             self.gamma = (0.5, gamma)
         else:
+            assert len(gamma) == 2, "gamma should be a number or pair of numbers."
             self.gamma = gamma
         assert len(self.gamma) == 2, "gamma should be a number or pair of numbers."