def METHOD_NAME(node, obj_name, matrix):
    context = bpy.context
    scene = context.scene
    meshes = bpy.data.meshes
    objects = bpy.data.objects
    mesh_name = node.mesh_to_clone
    collections = bpy.data.collections
    collection = collections.get(node.basedata_name)
    if not mesh_name:
        return
    if obj_name in objects:
        sv_object = objects[obj_name]
    else:
        mesh = meshes.get(mesh_name)
        sv_object = objects.new(obj_name, mesh)
        collection.objects.link(sv_object)
    # apply matrices
    if matrix:
        sv_object.matrix_local = list(zip(*matrix))
        sv_object.data.update()   # for some reason this _is_ necessary.