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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 _validate_auth_scheme(self, req):
 """ Check if the request has auth & the proper scheme Remember NOT to include the error related info in the WWW-Authenticate header for these conditions. :raise: AuthRequired """


        if not req.auth:
            raise AuthRequired(**{
                'detail': 'You must first login to access the requested '
                          'resource(s). Please retry your request using '
                          'OAuth 2.0 Bearer Token Authentication as '
                          'documented in RFC 6750. If you do not have an '
                          'access_token then request one at the token '
                          'endpdoint of: %s' % self.token_endpoint,
                'headers': self._error_headers,
                'links': 'tools.ietf.org/html/rfc6750#section-2.1',
            })
        elif req.auth_scheme != 'bearer':
            raise AuthRequired(**{
                'detail': 'Your Authorization header is using an unsupported '
                          'authentication scheme. Please modify your scheme '
                          'to be a string of: "Bearer".',
                'headers': self._error_headers,
                'links': 'tools.ietf.org/html/rfc6750#section-2.1',
            })