Calculate the password as per the API specification.
        :param username: 
        :param request_url:
        :return: password (string)

def get_password(self, username, request_url):
        """
        Calculate the password as per the API specification.
        :param username: 
        :param request_url:
        :return: password (string)
        """
        content = "%s%s%s" % (username, self.shared_secret, request_url)
        return hashlib.sha256(content.encode('utf8')).hexdigest()