method perform number import initi state diagram diagram type similar um lxxx diagram chang lai layer perspect layer perspect mutabl child layer perspect implement correct difficulti chang model lai us mainli layer manag gef control ad chang delet layer diagram param namespac uml model connect statechart diagram param machin state machin uml model author psager tigri jan oo setup object namespac object machin set namespac namespac state machin machin state diagram graph model gm creat graph model gm set home model namespac state machin gm set machin state machin state diagram render rend state diagram render singleton layer perspect lai layer perspect mutabl model facad namespac gm lai set graph node render rend lai set graph edg render rend set layer lai listen machin delet delet diagram model pump add model event listen state machin remov namespac 