describe replacing object in relayout

Author: chriddyp

plotly/widgets/graph_widget.py

@@ -364,6 +364,8 @@ def relayout(self, layout):
                 the title of an axis, combine the keys with a period
                 e.g. `xaxis.title`. To set a value of an element in an array,
                 like an axis's range, use brackets, e.g. 'xaxis.range[0]'.
+                To replace an entire nested object, just specify the value to
+                the sub-object. See example 4 below.
 
                 See all of the layout attributes in our reference documentation
                 https://plot.ly/python/reference/#Layout
@@ -393,6 +395,11 @@ def relayout(self, layout):
             ```
             graph.relayout({'xaxis.range[0]': -3})
             ```
+
+            Example 4 - Replace the entire xaxis object
+            ```
+            graph.relayout({'xaxis': {'title': 'Experimental results'}})
+            ```
         """
         # TODO: Add flat layout to graph_objs
         message = {