indicate that the default value will be changed to 'cubic'
@@ -2693,6 +2693,7 @@ class Network(object):
NxN S-parameters matrix at 0 Hz.
If None S-parameters at 0 Hz are determined by linear extrapolation.
kind : str or int, default is 'rational'
+ Default value will be changed to 'cubic' in future version.
Specifies the kind of interpolation as a string ('linear',
'nearest', 'zero', 'slinear', 'quadratic, 'cubic') or
as an integer specifying the order of the spline
