See https://github.com/plotly/plotly.py/pull/1240#issuecomment-436190981 These `button.args` assignments are valid, but raise validation errors as of 3.4.0 ```python import plotly.graph_objs as go button = go.layout.updatemenu.Button() button.method = 'animate' button.args = [['frame1', 'frame2']] button.args = [['frame1', 'frame2'], {'frame': [{'duration': 1500}, {'duration': 500}]}] ```