selfImDrawList handle on which this method operates.
Newly allocated draw-list clone containing the command, index, and vertex buffers; the native clone is not a borrowed window draw list.
Handles, mapped views/buffers, and draw data added via ImDrawData_AddDrawList share native ownership. Copied JavaScript draw callbacks remain callable across frames while the clone retains their commands. Textures and shared drawing state are still borrowed; cloning does not extend their lifetime.
Create a clone of the CmdBuffer/IdxBuffer/VtxBuffer.