code: def getFeature(self, prop):
          
  
          f = self.props.get(prop, None)
          if not f:
              return None
          if isinstance(f, Feature):
              return f
          if isinstance(f, tuple):
              if f[0]:
                  return f[0]
              elif f[1]:
                  return f[1]
              raise Exception("Getting value from a property with a constrain")
          if isinstance(f, list):
              return f
          raise Exception("Getting value from a not simple property.")
docs: Return the feature with that name.