Zhoverformat not allowed in heatmap for python

based on the doc page

zhoverformat is available in heatmap, but in python library it’s not allowed

----------------code snip-------------------
import plotly.plotly as py
import plotly.graph_objs as go

trace = go.Heatmap(z=[[1, 20, 30],
[20, 1, 60],
[30, 60, 1]],
py.iplot(data, filename=‘basic-heatmap’)
----------------code snip-------------------

and I got error message like below

PlotlyDictKeyError: ‘zhoverformat’ is not allowed in ‘heatmap’

Path To Error: [‘zhoverformat’]

Valid attributes for ‘heatmap’ at path [] under parents []:

['autocolorscale', 'colorbar', 'colorscale', 'connectgaps',
'customdata', 'customdatasrc', 'dx', 'dy', 'hoverinfo', 'hoverinfosrc',
'hoverlabel', 'ids', 'idssrc', 'legendgroup', 'name', 'opacity',
'reversescale', 'showlegend', 'showscale', 'stream', 'text', 'textsrc',
'transpose', 'type', 'uid', 'visible', 'x', 'x0', 'xaxis', 'xcalendar',
'xgap', 'xsrc', 'xtype', 'y', 'y0', 'yaxis', 'ycalendar', 'ygap',
'ysrc', 'ytype', 'z', 'zauto', 'zmax', 'zmin', 'zsmooth', 'zsrc']

Run <heatmap-object>.help('attribute') on any of the above.
‘’ is the object at []