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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 Mint(self, wallet, mint_to_addr, attachment_args, invoke_attrs=None):
 """ Call the "mintTokens" function of the smart contract. Args: wallet (neo.Wallets.Wallet):
 a wallet instance. mint_to_addr (str):
 public address of the account to mint the tokens to. attachment_args: (list):
 a list of arguments used to attach neo and/or gas to an invoke, eg ['--attach-gas=10.0','--attach-neo=3'] invoke_attrs: (list):
 a list of TransactionAttributes to be attached to the mint transaction Returns: tuple: InvocationTransaction: the transaction. int: the transaction fee. list: the neo VM evaluation stack results. """

        invoke_args = [self.ScriptHash.ToString(), 'mintTokens', []]

        invoke_args = invoke_args + attachment_args

        tx, fee, results, num_ops, engine_success = TestInvokeContract(wallet, invoke_args, None, True, from_addr=mint_to_addr, invoke_attrs=invoke_attrs)

        return tx, fee, results