title: Grabbing a response header value with reqwest in rust
body: <p>Ive mainly been experimenting with the reqwest module over the past few days to see what i can accomplish, but i came over a certain problem which im not able to resolve. Im trying to retrieve the a response headers value after doing a post request. The code in which i tried is</p>
  <pre><code>extern crate reqwest;
  
  fn main() {
     let client = reqwest::Client::new();
     let res = client
      .post(&quot;https://google.com&quot;)
      .header(&quot;testerheader&quot;, &quot;test&quot;)
      .send();
     println!(&quot;Headers:\n{:#?}&quot;, res.headers().get(&quot;content-length&quot;).unwrap());
  }
  </code></pre>
  <p>This code seems to return this error</p>
  <pre><code>error[E0599]: no method named `headers` found for opaque type `impl std::future::Future` in the current scope
  </code></pre>