text: import math
  
  import autofit as af
  from autofit.mock import mock_real
  
  
  def test_constructor():
      prior_model = af.PriorModel(mock_real.Circle)
  
      assert prior_model.prior_count == 1
  
      instance = prior_model.instance_from_prior_medians()
  
      assert instance.radius == 1.0
      assert instance.circumference == 2 * math.pi
  
  
  def test_alternative():
      prior_model = af.PriorModel(mock_real.Circle.with_circumference)
  
      assert prior_model.prior_count == 1
  
      instance = prior_model.instance_from_prior_medians()
  
      assert instance.circumference == 1.0
      assert instance.radius == 1.0 / (2 * math.pi)
  