text: import unittest
  import sys
  
  sys.path.insert(0, "..")
  from sections.sections import Ring
  import test_sections_generic as generic
  
  
  class TestPhysicalProperties(generic.TestPhysicalProperties, unittest.TestCase):
      
      @classmethod
      def setUpClass(cls):
          cls.sectclass  = Ring
          cls.dimensions = dict(ro=5.0, ri=3.0)
          cls.rp         = 5.0, 4.0
          cls.A          = 50.26548245743669
          cls._I0        = 427.2566008882119, 427.2566008882119, 0.0
          cls._I         = 427.2566008882119, 427.2566008882119, 0.0
          cls._cog       = 0.0, 0.0
      
      
      def test_check_dimensions(self):
      	self.assertRaises(ValueError, self.section.set_dimensions, ro=-1)
      	self.assertRaises(ValueError, self.section.set_dimensions, ro=0)
      	self.assertRaises(ValueError, self.section.set_dimensions, ri=-1)
      	self.assertRaises(ValueError, self.section.set_dimensions, ri=0)
      	self.assertRaises(ValueError, self.section.set_dimensions, ro=1, ri=2)
  
  
  if __name__ == "__main__":
      unittest.main()
  