position. If parent is non-NULL, then the row will be
made a child of parent. Otherwise, the row will be created at the toplevel.
If position is larger than the number of rows at that level, then the new
row will be inserted to the end of the list. iter will be changed to point
to this new row. The row will be empty after this function is called. To
fill in values, you need to call gtkTreeStoreSet or
gtkTreeStoreSetValue.gtkTreeStoreInsert(object, parent = NULL, position)objectparentGtkTreeIter, or NULL. [ allow-none ]positioniterGtkTreeIter to set to the new row