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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 _request_helper(self, url, params, method):
        '''API request helper method'''
        try:
            if method == 'POST':
                return self._request_post_helper(url, params)
            elif method == 'GET':
                return self._request_get_helper(url, params)
            raise VultrError('Unsupported method %s' % method)
        except requests.RequestException as ex:
            raise RuntimeError(ex)