docs: def remove_markable_layer(self):
          """
              Removes the markable layer (if exists) of the object (in memory)
              """
          if self.markable_layer is not None:
              this_node = self.markable_layer.get_node()
              self.root.remove(this_node)
          if self.header is not None:
              self.header.remove_lp('markables')