Not sure how to resolve this Rust compilation issue

sink-pin.rs

pub struct SqsSink {
    // ...snip...
    sqs_client: SqsClient,
    send_message_future: Option<std::pin::Pin<std::boxed::Box<dyn futures::Future<Output = std::result::Result<rusoto_sqs::SendMessageBatchResult, rusoto_core::RusotoError<rusoto_sqs::SendMessageBatchError>>> + std::marker::Send>>>,
}

impl Sink<Arc<Box<dyn MessageChunk>>> for SqsSink {
    type Error = ();
    // ...snip...
    fn poll_flush(mut self: std::pin::Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
        // ...snip...

        let fut = self.sqs_client.send_message_batch(send_message_batch_request);
        self.send_message_future = Some(fut);

        // ...snip...
    }
    // ...snip...
}

/*
Causes compile error:

error[E0759]: `self` has an anonymous lifetime `'_` but it needs to satisfy a `'static` lifetime requirement
  --> src/sqs_sink.rs:80:31
   |
45 |     fn poll_flush(mut self: std::pin::Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
   |                             ------------------------ this data with an anonymous lifetime `'_`...
...
80 |                     let fut = self.sqs_client.send_message_batch(send_message_batch_request);
   |                               ^^^^^^^^^^^^^^^ ...is captured here...
81 |                     self.send_message_future = Some(fut);
   |                                                --------- ...and is required to live as long as `'static` here

*/