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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_accounts(self, username=None):
 """ Get a list of accounts owned by the user. Parameters username : string The name of the user. Note: This is only required on the sandbox, on production systems your access token will identify you. See more: http://developer.oanda.com/rest-sandbox/accounts/#-a-name-getaccountsforuser-a-get-accounts-for-a-user """

        url = "{0}/{1}/accounts".format(self.domain, self.API_VERSION)
        params = {"username": username}
        try:
            return self._Client__call(uri=url, params=params, method="get")
        except RequestException:
            return False
        except AssertionError:
            return False