code: def is_new_namespace_preorder( self, namespace_id_hash, lastblock=None ):
          
          if lastblock is None:
              lastblock = self.lastblock 
  
          preorder = namedb_get_namespace_preorder( self.db, namespace_id_hash, lastblock )
          if preorder is not None:
              return False 
          else:
              return True
docs: Given a namespace preorder hash, determine whether or not is is unseen before.