title: Parameter names with ES6?
body: <p>I have defined a function like:</p>
  
  <pre><code>function call_api(url, callback, query = {}, body = {})
  </code></pre>
  
  <p>I expected a syntax where I can provide body and skip query:</p>
  
  <pre><code>call_api('/api/clients/new', function(x){console.log(x)}, body={1:2})
  </code></pre>
  
  <p>But I have to use this workaround:</p>
  
  <pre><code>call_api('/api/clients/new', function(x){console.log(x)}, {}, {1:2})
  </code></pre>
  
  <p>Even if I provide <code>body=</code>, it appears its appearing as the <code>query</code> parameter. I use Babel with Webpack. I tried the syntax in Chrome console and in Webpack source.</p>
  
  <p>Is such a syntax supported by ES6? How does it work?</p>