FA multi-source example #86

Is there an example of using FA in the multi-source context? Going off of the documentation, I thought the following should work but it's failing:

FA can be used for multi-source DA by giving list of source data for arguments Xs, ys of fit method : Xs = [Xs1, Xs2, …], ys = [ys1, ys2, …]

Xs1, Xs2, Xs3 = pd.DataFrame(...), pd.DataFrame(...), pd.DataFrame(...)
ys1, ys2, ys3 = [...], [...], [...]
Xss = [
  Xs1,
  Xs2,
  Xs3,
]
yss = [
  ys1,
  ys2,
  ys3
]
model.fit(Xss, yss)

i.e. Xs1-3 are Pandas dataframes containing source features and yss1-3 are each a list of observed values.

But the output is: ValueError: Expected 2D array, got 1D array instead: [contents of Xss]