[DEBUG] manage mask=None in watershed.py

Author: gauzias

examples/example_watershed.py

@@ -28,7 +28,7 @@
 ###############################################################################
 # loading an examplar mesh and corresponding texture
 path_to_mesh = "../examples/data/example_mesh.gii"
-path_to_mask = ""
+path_to_mask = None
 path_to_output = ""
 
 mesh = sio.load_mesh(path_to_mesh)
@@ -48,7 +48,7 @@
 
 ###############################################################################
 # define the exclusion mask (cingular pole)
-if path_to_mask:
+if path_to_mask is not None:
     mask = sio.load_texture(path_to_mask).darray[0]
 else:
     mask = None