code: def can_editions(self):
          
          chain = BlockchainSpider.chain(self._tree, REGISTERED_PIECE_CODE)
  
          if len(chain) == 0:
              self.reason = 'Master edition not yet registered'
              return False
  
          number_editions = chain[0]['number_editions']
          if number_editions != 0:
              self.reason = 'Number of editions was already registered for this piece'
              return False
  
          return True
docs: bool: :const:`True` if :attr:`address` can register the number of
          editions of :attr:`piece_address` else :const:`False`.
  
          In order to register the number of editions:
  
          1. There needs to a least one transaction for the :attr:`piece_address`
          (the registration of the master edition).
  
          2. A piece with address :attr:`piece_address` needs to be registered
          with ``'ASCRIBESPOOL01PIECE'`` (master edition).
  
          3. The number of editions should have not been set yet (no tx with
          verb ``'ASCRIBESPOOLEDITIONS'``).