'Checks if the block is a fold trigger.
:param block: block to check
:return: True if the block is a fold trigger (represented as a node in
the fold panel)'

@staticmethod
def is_fold_trigger(block):

    if (block is None):
        return False
    state = block.userState()
    if (state == (-1)):
        state = 0
    return bool((state & 67108864))
