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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 parse_block(self, block_id, txs):
 """ Given the sequence of transactions in a block, turn them into a sequence of virtual chain operations. Return the list of successfully-parsed virtualchain transactions """

        ops = []
        for i in range(0,len(txs)):
            tx = txs[i]
            op = self.parse_transaction(block_id, tx)
            if op is not None:
                ops.append( op )
            
        return ops