fixup! Add a placeholder for bokeh engine

Author: rs2

pandas/plotting/_core.py

@@ -2479,8 +2479,10 @@ class BokehFramePlotMethods(base.FramePlotMethods):
     import numpy as np
     import bokeh
     from bokeh.io import output_notebook, INLINE
+
+    output_notebook(hide_banner=True)
     pd.set_option('plotting.engine', 'bokeh')
-    df = pd.DataFrame(np.random.rand(5, 3))
+    df = pd.DataFrame(np.random.rand(5, 3), columns='foo bar baz'.split())
     df.plot()
     """