Default overlay=True for WMS

Author: ocefpaf

folium/features.py

@@ -18,7 +18,7 @@
 class WmsTileLayer(TileLayer):
     def __init__(self, url, name=None,
                  format=None, layers=None, transparent=True,
-                 attribution=None):
+                 attribution=None, overlay=True):
         """
         TODO docstring here
 
@@ -29,6 +29,7 @@ def __init__(self, url, name=None,
         self.url = url
         self.format = format
         self.layers = layers
+        self.overlay = overlay
         self.transparent = transparent
         # if attribution is None:
         #     raise ValueError('WMS must'