async fn describe_association(
        &self,
        input: DescribeAssociationRequest,
    ) -> Result<DescribeAssociationResult, RusotoError<DescribeAssociationError>> {
        let mut request = self.new_signed_request("POST", "/");
        request.add_header("x-amz-target", "AmazonSSM.DescribeAssociation");
        let encoded = serde_json::to_string(&input).unwrap();
        request.set_payload(Some(encoded));

        let response = self
            .sign_and_dispatch(request, DescribeAssociationError::from_response)
            .await?;
        let mut response = response;
        let response = response.buffer().await.map_err(RusotoError::HttpDispatch)?;
        proto::json::ResponsePayload::new(&response).deserialize::<DescribeAssociationResult, _>()
    }
<p>Describes the association for the specified target or instance. If you created the association by using the <code>Targets</code> parameter, then you must retrieve the association by using the association ID. If you created the association by specifying an instance ID and a Systems Manager document, then you retrieve the association by specifying the document name and the instance ID. </p>
rusoto/services/ssm/src/generated.rs