code: def RemoveTransaction(self, tx):
          
          if BC.Default() is None:
              return False
  
          if not BC.Default().ContainsTransaction(tx.Hash):
              return False
  
          if tx.Hash.ToBytes() in self.MemPool:
              del self.MemPool[tx.Hash.ToBytes()]
              return True
  
          return False
docs: Remove a transaction from the memory pool if it is found on the blockchain.
  
          Args:
              tx (neo.Core.TX.Transaction): instance.
  
          Returns:
              bool: True if successfully removed. False otherwise.