title: Mismatch between apple developer documentation and functions in swift playgrounds
body: <p>In the apple developer documentation <a href="https://developer.apple.com/documentation/spritekit/skaction/1417770-applyimpulse" rel="nofollow noreferrer">here</a>, the <code>applyImpluse</code> function from <code>SpriteKit</code> seems to have two parameters: <code>impulse:</code> and <code>duration:</code>. However, when I go into Swift Playgrounds and create a playground, after importing SpriteKit I seem to get this function in my auto complete: <code>dot.physicsBody?.applyImpulse(CGVector)</code> (where dot is a <code>SKShapeNode</code>).</p>
  <p>Now, If you noticed, the function only takes one parameter, which is impulse, but not duration. Trying to insert a <code>duration:</code> parameter raises errors, and playgrounds, tries to suggest different function with a <code>at:</code> parameter. The same thing happens with applyForce.</p>
  <p>This also happens if dot is a <code>SKSpriteNode</code>.</p>
  <p>I am confused, as this shouldn't happen. Have I misread the docs, or is there something I am missing?</p>