text: import pytest
  from hypothesis import given
  
  from gon.base import Contour
  from . import strategies
  
  
  @given(strategies.contours)
  def test_basic(contour: Contour) -> None:
      result = contour.validate()
  
      assert result is None
  
  
  @given(strategies.invalid_contours)
  def test_invalid_contour(contour: Contour) -> None:
      with pytest.raises(ValueError):
          contour.validate()
  