Fix incorrect list.extend usage
Fix incorrect list.extend usage

girder/girder,manthey/girder,Kitware/girder,RafaelPalomar/girder,manthey/girder,manthey/girder,Kitware/girder,Kitware/girder,RafaelPalomar/girder,Kitware/girder,RafaelPalomar/girder,girder/girder,RafaelPalomar/girder,RafaelPalomar/girder,girder/girder,manthey/girder,girder/girder