async fn update_association(
        &self,
        input: UpdateAssociationRequest,
    ) -> Result<UpdateAssociationResult, RusotoError<UpdateAssociationError>> {
        let mut request = self.new_signed_request("POST", "/");
        request.add_header("x-amz-target", "AmazonSSM.UpdateAssociation");
        let encoded = serde_json::to_string(&input).unwrap();
        request.set_payload(Some(encoded));

        let response = self
            .sign_and_dispatch(request, UpdateAssociationError::from_response)
            .await?;
        let mut response = response;
        let response = response.buffer().await.map_err(RusotoError::HttpDispatch)?;
        proto::json::ResponsePayload::new(&response).deserialize::<UpdateAssociationResult, _>()
    }
<p><p>Updates an association. You can update the association name and version, the document version, schedule, parameters, and Amazon S3 output. </p> <p>In order to call this API action, your IAM user account, group, or role must be configured with permission to call the <a>DescribeAssociation</a> API action. If you don&#39;t have permission to call DescribeAssociation, then you receive the following error: <code>An error occurred (AccessDeniedException) when calling the UpdateAssociation operation: User: &lt;user<em>arn&gt; is not authorized to perform: ssm:DescribeAssociation on resource: &lt;resource</em>arn&gt;</code> </p> <important> <p>When you update an association, the association immediately runs against the specified targets.</p> </important></p>
rusoto/services/ssm/src/generated.rs