def pop_defblock(self):
    if (not self.defblock_stack):
        return self.defblock
    block = self.defblock
    self.defblock = self.defblock_stack.pop(0)
    return block
def pop_defblock(self):
    if (not self.defblock_stack):
        return self.defblock
    block = self.defblock
    self.defblock = self.defblock_stack.pop(0)
    return block