Fixes the following runtime error for me when benchmarking:
thread 'main' panicked at 'called `Result::unwrap()` on an `Err`
value: Error: Unregistered error class: "Error"
Connection reset by peer (os error 104)
Classes of errors returned from ops should be registered via
Deno.core.registerErrorClass().
at processResponse (deno:core/core.js:219:13)
at Object.jsonOpAsync (deno:core/core.js:240:12)
at async read (http_bench_json_ops.js:29:21)
at async serve (http_bench_json_ops.js:45:19)',
core/examples/http_bench_json_ops.rs:260:28