docs: def addvector(self, vec):
          """
          add a vector object to the layer of the current Vector object
  
          Parameters
          ----------
          vec: Vector
              the vector object to add
          merge: bool
              merge overlapping polygons?
  
          Returns
          -------
  
          """
          vec.layer.ResetReading()
          for feature in vec.layer:
              self.layer.CreateFeature(feature)
          self.init_features()
          vec.layer.ResetReading()