def get_block_tuple(block_inst):
    """
    Returns the canned block tuple for use in StreamField and StreamBlock definitions (but NOT in StructBlocks!).
    We use this everywhere so that our code consistently generates the same tuple at every organiziational level.
    """
    try:
        return block_inst.get_block_tuple()
    except AttributeError:
        # If the block instance hasn't got a get_block_tuple() method, build the default tuple.
        return (block_inst.__class__.__name__, block_inst)