code: def unregister_project(self, project_node, raise_exception=False):
          
  
          if raise_exception:
              if not project_node in self.list_project_nodes():
                  raise foundations.exceptions.ProgrammingError(
                      "{0} | '{1}' project 'ProjectNode' isn't registered!".format(
                          self.__class__.__name__, project_node))
  
          LOGGER.debug("> Unregistering '{0}' project 'ProjectNode'.".format(project_node))
  
          parent = project_node.parent
          row = project_node.row()
          self.beginRemoveRows(self.get_node_index(parent), row, row)
          parent.remove_child(row)
          self.endRemoveRows()
  
          self.project_unregistered.emit(project_node)
  
          return project_node
docs: Unregisters given :class:`umbra.components.factory.scriptProject.nodes.ProjectNode` class Node from the Model.
  
          :param project_node: ProjectNode to unregister.
          :type project_node: ProjectNode
          :param raise_exception: Raise the exception.
          :type raise_exception: bool
          :return: ProjectNode.
          :rtype: ProjectNode