Slight doc change helpers

Author: stefanradev93

bayesflow/helper_classes.py

@@ -95,6 +95,9 @@ def __call__(self, batch_in):
             forward_dict[key_none] = None
         return forward_dict
 
+    def __len__(self):
+        return len(self.data)
+
     def __iter__(self):
         return map(self, self.data)
 

bayesflow/helper_functions.py

@@ -28,7 +28,8 @@
 
 
 def check_tensor_sanity(tensor, logger):
-    """Tests for the present of NaNs and Infs in a tensor."""
+    """Tests for the presence of NaNs and Infs in a tensor."""
+
     if tf.executing_eagerly():
         if tf.reduce_any(tf.math.is_nan(tensor)):
             num_na = tf.reduce_sum(tf.cast(tf.math.is_nan(tensor), tf.int8)).numpy()