perform number import initi em us diagram em creat graph model diagram set namespac suppli chang em lai em em layer perspect em em layer perspect mutabl em child em layer perspect em implement correct difficulti chang model em lai em us mainli em layer manag em gef control ad chang delet item layer diagram set render suitabl us diagram em note em declar clear class allow invok method param handl namespac us diagram author psager tigri jan overrid set namespac object handl model facad namespac handl defin log lp log granular type statement lp log local nest ifdef usecasediagram log error illeg argument object handl namespac endif illeg argument except illeg argument object handl namespac object handl set namespac us diagram graph model gm us diagram graph model graph model gm set home model layer perspect lai layer perspect mutabl model facad gm us diagram render rend us diagram render lai set graph node render rend lai set graph edg render rend set layer lai render singleton 