code: def can_unconsign(self):
          
          chain = BlockchainSpider.chain(self._tree, self.edition_number)
          if len(chain) == 0:
              self.reason = 'Master edition not yet registered'
              return False
  
          chain = BlockchainSpider.strip_loan(chain)
          action = chain[-1]['action']
          piece_address = chain[-1]['piece_address']
          edition_number = chain[-1]['edition_number']
          to_address = chain[-1]['to_address']
  
          if action != 'CONSIGN' or piece_address != self.piece_address or edition_number != self.edition_number or to_address != self.address:
              self.reason = 'Edition number {} is not consigned to {}'.format(self.edition_number, self.address)
              return False
  
          return True
docs: bool: :const:`True` if :attr:`address` can unconsign the edition
          :attr:`edition_number` of :attr:`piece_address` else :const:`False`.
  
          If the last transaction is a consignment of the edition to the user.