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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 account(self, account=None):
        ''' Fetches account information and stores the
        result in a class variable. Returns that variable
        if the account has not changed.
        '''
        for num_of_retries in range(default.max_retry):
            if account is None:
                account = self.mainaccount
            if account == self.checkedaccount:
                return self.accountinfo
            self.checkedaccount = account
            try:
                self.accountinfo = self.steem_instance().get_account(account)
            except Exception as e:
                self.util.retry(("COULD NOT GET ACCOUNT INFO FOR " + str(account)), 
                    e, num_of_retries, default.wait_time)
                self.s = None
            else:
                if self.accountinfo is None:
                    self.msg.error_message("COULD NOT FIND ACCOUNT: " + str(account))
                    return False
                else:
                    return self.accountinfo