msng_new()
instantiates a newmsng
node.msng_type()
checks if the node is amsng
node.msng_<child>_get()
returns the<child>
node ofmsng
.msng_<child>_set()
sets the new<child>
and deletes the old<child>
.msng_<child>_rep()
sets the new<child>
and returns the old<child>
.