Separator within an EnumProperty I'm trying to insert an separator to an EnumProperty like used in the Operator object.select_by_type. This is the Property used by this Operator (blender-2.77a.tar/blender-2.77a/source/blender/makesrna/intern/rna_object.c - it's written in C):

EnumPropertyItem rna_enum_object_type_items[] = {
    {OB_MESH, "MESH", 0, "Mesh", ""},
    OBTYPE_CU_CURVE,
    OBTYPE_CU_SURF,
    {OB_MBALL, "META", 0, "Meta", ""},
    OBTYPE_CU_FONT,
    {0, "", 0, NULL, NULL},
    {OB_ARMATURE, "ARMATURE", 0, "Armature", ""},
    {OB_LATTICE, "LATTICE", 0, "Lattice", ""},
    {OB_EMPTY, "EMPTY", 0, "Empty", ""},
    {0, "", 0, NULL, NULL},
    {OB_CAMERA, "CAMERA", 0, "Camera", ""},
    {OB_LAMP, "LAMP", 0, "Lamp", ""},
    {OB_SPEAKER, "SPEAKER", 0, "Speaker", ""},
    {0, NULL, 0, NULL, NULL}
};


The line {0, "", 0, NULL, NULL} creates a seperator (In Python the tupel is sorted different from the C-one). In Python I can't use a tupel like ("", None, None) within the item-set and a tupel like ("", "", "") creates a new column (described here: https://blenderartists.org/forum/showthread.php?409613-How-to-create-columns-in-operator_menu_enum-SOLVED).

How can I add a seperator to an EnumProperty in Python?

Thanks.
From the documentation for 2.9:

When an item only contains 4 items they define (identifier, name, description, number).
Separators may be added using None instead of a tuple. For dynamic values a callback can be passed which returns a list in the same format as the static list.

This is conspicuously absent in the documentation for 2.79, so there may not have been an easy way to do it in Python when this question was asked. But for newer versions, you can just use a straight None instead of a tuple.