ExecuteServiceEndpointRequest.
        [Preview API] Proxy for a GET request defined by a service endpoint.
        :param :class:`<ServiceEndpointRequest> <azure.devops.v5_0.service_endpoint.models.ServiceEndpointRequest>` service_endpoint_request: Service endpoint request.
        :param str project: Project ID or project name
        :param str endpoint_id: Id of the service endpoint.
        :rtype: :class:`<ServiceEndpointRequestResult> <azure.devops.v5_0.service_endpoint.models.ServiceEndpointRequestResult>`

def execute_service_endpoint_request(self, service_endpoint_request, project, endpoint_id):
        """ExecuteServiceEndpointRequest.
        [Preview API] Proxy for a GET request defined by a service endpoint.
        :param :class:`<ServiceEndpointRequest> <azure.devops.v5_0.service_endpoint.models.ServiceEndpointRequest>` service_endpoint_request: Service endpoint request.
        :param str project: Project ID or project name
        :param str endpoint_id: Id of the service endpoint.
        :rtype: :class:`<ServiceEndpointRequestResult> <azure.devops.v5_0.service_endpoint.models.ServiceEndpointRequestResult>`
        """
        route_values = {}
        if project is not None:
            route_values['project'] = self._serialize.url('project', project, 'str')
        query_parameters = {}
        if endpoint_id is not None:
            query_parameters['endpointId'] = self._serialize.query('endpoint_id', endpoint_id, 'str')
        content = self._serialize.body(service_endpoint_request, 'ServiceEndpointRequest')
        response = self._send(http_method='POST',
                              location_id='cc63bb57-2a5f-4a7a-b79c-c142d308657e',
                              version='5.0-preview.1',
                              route_values=route_values,
                              query_parameters=query_parameters,
                              content=content)
        return self._deserialize('ServiceEndpointRequestResult', response)