title: How to access already initialised node within another method SpriteKit
body: <p>In an application I have, I initialise a SKSpriteNode (Ball) the <code>didMoveToView</code> method. I have a method that picks up on swipes up (That works fine, I tested it).</p>
  
  <p>When that is called, it calls a method called <code>[self jump];</code> 
  In this method, I want it to run a few actions using the SKSpriteNode, <code>Ball</code>.</p>
  
  <p>I used to know, but I have forgotten the code that allows you to access already initialised nodes. Say if I was going to write <code>[Ball runAction:myAction];</code>
  , the compiler will replace 'Ball' with '_Ball'.</p>
  
  <p>How can I manipulate the SKSpriteNode 'Ball' within another method? 
  I don't think that I need to add any code but if it helps I will comply.
  Thank you in advance.</p>