Plotly Figure. How to get the number of rows and cols?

I create a Plotly Figure instance this way:

fig = go.Figure()
fig = make_subplots(rows=3, cols=1, shared_xaxes=True, row_width=[0.3, 0.3, 0.4])

Lets assume that now I do not know how many rows and cols the Figure instance has. How can I obtain these values? For example, I expect something like this:

rows = fig.get_rows_num()
cols = fig.get_cols_num()

I appreciate any help.