import { WrappedRequest } from "https://deno.land/x/opine@2.3.4/src/request.ts";
Check if the incoming request contains the "Content-Type"
header field, and it contains the give mime type.
Examples:
// With Content-Type: text/html; charset=utf-8
req.is('html');
req.is('text/html');
req.is('text/*');
// => true
// When Content-Type is application/json
req.is('json');
req.is('application/json');
req.is('application/*');
// => true
req.is('html');
// => false
Parameters
this: OpineRequest