Add comment about method.
@@ -63,7 +63,7 @@ DEFAULT_MAX_ROWS = 5000
# Rendering configuration
#*************************************************************************
-
+# This is added to TopLevelMixin as a method if MIME rendering is enabled
def _repr_mimebundle_(self, include, exclude, **kwargs):
"""Return a MIME-bundle for rich display in the Jupyter Notebook."""
spec = self.to_dict()
