title: No exact matches in call to instance method error message in Swift
body: <p>I never get this before, What is the meaning of this error message in Swift:</p>
  <blockquote>
  <p>No exact matches in call to instance method 'dataTask(with:completionHandler:)'</p>
  </blockquote>
  <p>Here is my code block:</p>
  <pre><code>var request: NSMutableURLRequest? = nil
  let task = URLSession.shared.dataTask(
              with: request,
              completionHandler: { data, response, error in
                  DispatchQueue.main.async(execute: {
                    /// ...
                  })
              })
  task.resume()
  </code></pre>
  <h3>Bug Report</h3>
  <p>Reported via feedbackassistant.apple.com: <strong>FB7717686</strong></p>