Apply better type annotation

pystencils/gpu/indexing.py

@@ -138,7 +138,7 @@ class BlockIndexing(AbstractIndexing):
         device_number: device number of the used GPU. By default, the zeroth device is used.
     """
 
-    def __init__(self, iteration_space: Tuple[slice], data_layout: Tuple,
+    def __init__(self, iteration_space: Tuple[slice], data_layout: Tuple[int],
                  block_size=(128, 2, 1), permute_block_size_dependent_on_layout=True, compile_time_block_size=False,
                  maximum_block_size=(1024, 1024, 64), device_number=None):
         super(BlockIndexing, self).__init__(iteration_space, data_layout)