You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: opentelemetry.rs
    path of file: ./repos/async-graphql/src/extensions
    
    the code of the file until where you have to start completion: use std::sync::Arc;

use async_graphql_parser::types::ExecutableDocument;
use async_graphql_value::Variables;
use futures_util::{stream::BoxStream, TryFutureExt};
use opentelemetry::{
    trace::{FutureExt, Spa
    
    async fn request(&self, ctx: &ExtensionContext<'_>, next: NextRequest<'_>) -> Response {
        next.run(ctx)
            .with_context(OpenTelemetryContext::current_with_span(
                self.tracer
                    .span_builder("request")
                    .with_kind(SpanKind::Server)
                    .start(&*self.tracer),
            ))
            .await
    }