How does Prophet suggest default values of hyperparameters?

With reference to https://facebook.github.io/prophet/docs/diagnostics.html, Prophet suggests the following default values for certain hyperparamters:
changepoint_prior_scale : 0.05,
seasonality_prior_scale: 10,
holidays_prior_scale: 10,
seasonality_mode: 'additive'
changepoint_range: '0.8'

My question is, were there any benchmarks done to arrive at these numbers?
If yes, can you point me to those benchmark results.