async fn associate_entity_to_thing(
        &self,
        input: AssociateEntityToThingRequest,
    ) -> Result<AssociateEntityToThingResponse, RusotoError<AssociateEntityToThingError>> {
        let mut request = self.new_signed_request("POST", "/");
        request.add_header(
            "x-amz-target",
            "IotThingsGraphFrontEndService.AssociateEntityToThing",
        );
        let encoded = serde_json::to_string(&input).unwrap();
        request.set_payload(Some(encoded));

        let response = self
            .sign_and_dispatch(request, AssociateEntityToThingError::from_response)
            .await?;
        let mut response = response;
        let response = response.buffer().await.map_err(RusotoError::HttpDispatch)?;
        proto::json::ResponsePayload::new(&response)
            .deserialize::<AssociateEntityToThingResponse, _>()
    }
<p>Associates a device with a concrete thing that is in the user's registry.</p> <p>A thing can be associated with only one device at a time. If you associate a thing with a new device id, its previous association will be removed.</p>
rusoto/services/iotthingsgraph/src/generated.rs