new_contents: """Test code for visibilty.py."""
  
  import pytest
  from visibility import decdeg2dms, StarObsPlot, VisibilityPlot
  
  
  @pytest.mark.parametrize("test_input,expected", [
      (0, (0, 0, 0)),
      (33.33, (33, 19, 48)),
      (-45.5125, (-45, 30, 45)),
      (60.60, (60, 36, 0)),
      (-90, (-90, 0, 0)),
  ])
  def test_decdeg2dms(test_input, expected):
      """Test of converting decimal declination."""
      # Possibly limit to +/-90 deg somewhere.
      assert decdeg2dms(test_input) == expected
  
subject: Add a test for decimal declination conversion.