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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def AddTransaction(self, tx):
 """ Add a transaction to the memory pool. Args: tx (neo.Core.TX.Transaction):
 instance. Returns: bool: True if successfully added. False otherwise. """

        if BC.Default() is None:
            return False

        if tx.Hash.ToBytes() in self.MemPool.keys():
            return False

        if BC.Default().ContainsTransaction(tx.Hash):
            return False

        if not tx.Verify(self.MemPool.values()):
            logger.error("Verifying tx result... failed")
            return False

        self.MemPool[tx.Hash.ToBytes()] = tx

        return True