implement may_be_none() for CloneNode
implement may_be_none() for CloneNode

madjar/cython,madjar/cython,acrispin/cython,ABcDexter/cython,madjar/cython,JelleZijlstra/cython,dahebolangkuan/cython,scoder/cython,ABcDexter/cython,larsmans/cython,acrispin/cython,slonik-az/cython,hpfem/cython,achernet/cython,cython/cython,mcanthony/cython,ChristopherHogan/cython,hickford/cython,ABcDexter/cython,larsmans/cython,rguillebert/CythonCTypesBackend,madjar/cython,fperez/cython,c-blake/cython,mcanthony/cython,fperez/cython,slonik-az/cython,da-woods/cython,fabianrost84/cython,mrGeen/cython,marscher/cython,achernet/cython,hpfem/cython,fperez/cython,mcanthony/cython,achernet/cython,acrispin/cython,roxyboy/cython,marscher/cython,slonik-az/cython,hhsprings/cython,acrispin/cython,fabianrost84/cython,JelleZijlstra/cython,ChristopherHogan/cython,andreasvc/cython,fabianrost84/cython,cython/cython,andreasvc/cython,hpfem/cython,cython/cython,dahebolangkuan/cython,achernet/cython,slonik-az/cython,roxyboy/cython,hickford/cython,da-woods/cython,c-blake/cython,mcanthony/cython,roxyboy/cython,fabianrost84/cython,marscher/cython,encukou/cython,hhsprings/cython,marscher/cython,JelleZijlstra/cython,hickford/cython,ChristopherHogan/cython,dahebolangkuan/cython,mrGeen/cython,c-blake/cython,mcanthony/cython,achernet/cython,c-blake/cython,JelleZijlstra/cython,andreasvc/cython,encukou/cython,slonik-az/cython,mrGeen/cython,c-blake/cython,roxyboy/cython,andreasvc/cython,hhsprings/cython,hpfem/cython,mrGeen/cython,rguillebert/CythonCTypesBackend,mrGeen/cython,da-woods/cython,hpfem/cython,hickford/cython,scoder/cython,dahebolangkuan/cython,encukou/cython,acrispin/cython,dahebolangkuan/cython,andreasvc/cython,madjar/cython,rguillebert/CythonCTypesBackend,ABcDexter/cython,scoder/cython,da-woods/cython,rguillebert/CythonCTypesBackend,encukou/cython,larsmans/cython,cython/cython,hhsprings/cython,larsmans/cython,scoder/cython,hhsprings/cython,JelleZijlstra/cython,fabianrost84/cython,marscher/cython,roxyboy/cython,larsmans/cython,hickford/cython,fperez/cython,fperez/cython,encukou/cython,ABcDexter/cython