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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 __get_all_child_accounts_as_array(self, account: Account) -> List[Account]: """ Returns the whole tree of child accounts in a list """

        result = []
        # ignore placeholders ? - what if a brokerage account has cash/stocks division?
        # if not account.placeholder:
        # continue
        result.append(account)

        for child in account.children:
            sub_accounts = self.__get_all_child_accounts_as_array(child)
            result += sub_accounts

        return result