UPDATE:
@Matt Long, I have tried reach my aim with dopuserlibrary(),
dropuserlibraryobject(views().find("modules/ProcessFlow/DragDropLibrary/Basic/Assign Labels"),model().find("Tools/ProcessFlow/ProcessFlow"));
but unfortunatelly this solution does not work. I have also tried just paste "Assign Label" node into "ProcessFlow" node but then I had an error:
"exception: Exception caught in TreeNode::callMemberFunction() c++/dll execution. Throwing... VIEW:/active/MainPanel/BackPanel/SplitterXPane/SplitterYPane/SplitterXPane/TabPane~3/TabControl/ProcessFlow2>eventfunctions/onDrawCallback c: VIEW:/active/MainPanel/BackPanel/SplitterXPane/SplitterYPane/SplitterXPane/TabPane~3/TabControl/ProcessFlow2 thisClass: VIEW:/active/MainPanel/BackPanel/SplitterXPane/SplitterYPane/SplitterXPane/TabPane~3/TabControl/ProcessFlow2 exception: FlexScript exception: VIEW:/active/MainPanel/BackPanel/SplitterXPane/SplitterYPane/SplitterXPane/TabPane~3/TabControl/ProcessFlow2>eventfunctions/OnDraw c: VIEW:/active/MainPanel/BackPanel/SplitterXPane/SplitterYPane/SplitterXPane/TabPane~3/TabControl/ProcessFlow2 exception: Exception caught in TreeNode::callMemberFunction() c++/dll execution. Throwing... VIEW:/active/MainPanel/BackPanel/SplitterXPane/SplitterYPane/SplitterXPane/TabPane~3/TabControl/ProcessFlow2>eventfunctions/onDrawCallback c: VIEW:/active/MainPanel/BackPanel/SplitterXPane/SplitterYPane/SplitterXPane/TabPane~3/TabControl/ProcessFlow2 thisClass: VIEW:/active/MainPanel/BackPanel/SplitterXPane/SplitterYPane/SplitterXPane/TabPane~3/TabControl/ProcessFlow2 exception: FlexScript exception: VIEW:/active/MainPanel/BackPanel/SplitterXPane/SplitterYPane/SplitterXPane/TabPane~3/TabControl/ProcessFlow2>eventfunctions/OnDraw c: VIEW:/active/MainPanel/BackPanel/SplitterXPane/SplitterYPane/SplitterXPane/TabPane~3/TabControl/ProcessFlow2"
I have also tried to fire onDropCallback function but there was no effect. Maybe I've made some mistake in code.
Do you have an idea what should I do now?