predict_hazard method of GeneralizedGammaRegressionFitter is error

[phruekc]

There is error regarding to input dimensions of GeneralizedGammaRegressionFitter.
See this example;

from lifelines import GeneralizedGammaRegressionFitter
from lifelines.datasets import load_regression_dataset
regression_dataset = load_regression_dataset()

ggr = GeneralizedGammaRegressionFitter()
ggr.fit_intercept = True
ggr.fit(regression_dataset, 'T', event_col='E')

plotting Survival Function works normally

ggr.plot_partial_effects_on_outcome('var1', values=np.arange(-7,8), cmap='coolwarm')
but plotting Hazard function gives this value error regarding to dimensions of input.

ggr.plot_partial_effects_on_outcome('var1', values=np.arange(-7,8), cmap='coolwarm', y='hazard') 

>>> ValueError: Length of values (200) does not match length of index (15)

By the way, I've drilled down to the source code and found that this error comes from self.predict_hazard

Please kindly let me know how to make it works.