Add typing annotations to detection/image_list (#4602)

* Add typing for imagelist, move params to docstring

* Add docs

mypy.ini

@@ -25,10 +25,6 @@ ignore_errors = True
 
 ignore_errors = True
 
-[mypy-torchvision.models.detection.image_list]
-
-ignore_errors = True
-
 [mypy-torchvision.models.detection.transform]
 
 ignore_errors = True

torchvision/models/detection/image_list.py

@@ -10,14 +10,13 @@ class ImageList(object):
     varying sizes) as a single tensor.
     This works by padding the images to the same size,
     and storing in a field the original sizes of each image
+
+    Args:
+        tensors (tensor): Tensor containing images.
+        image_sizes (list[tuple[int, int]]): List of Tuples each containing size of images.
     """
 
-    def __init__(self, tensors: Tensor, image_sizes: List[Tuple[int, int]]):
-        """
-        Args:
-            tensors (tensor)
-            image_sizes (list[tuple[int, int]])
-        """
+    def __init__(self, tensors: Tensor, image_sizes: List[Tuple[int, int]]) -> None:
         self.tensors = tensors
         self.image_sizes = image_sizes