code: def _check_zero_size(self):
          '''
          Checks for zero height or zero width blocks and flags the occurrence.
  
          Returns:
              True if the block is size 0.
          '''
          block_zero = self.end[0] <= self.start[0] or self.end[1] <= self.start[1]
          if block_zero:
              self.flag_change(self.flags, 'fatal', worksheet=self.worksheet,
                               message=self.FLAGS['0-size'])
          return block_zerf _check_zero_size(self):
          '''
          Checks for zero height or zero width blocks and flags the occurrence.
  
          Returns:
              True if the block is size 0.
          '''
          block_zero = self.end[0] <= self.start[0] or self.end[1] <= self.start[1]
          if block_zero:
              self.flag_change(self.flags, 'fatal', worksheet=self.worksheet,
                               message=self.FLAGS['0-size'])
          return block_zero
docs: Checks for zero height or zero width blocks and flags the occurrence.
  
          Returns:
              True if the block is size 0.