title: How i can call functions from other class? Swift, Xcode
body: <p>I have a class ACCreateObject. They have a function circlePhysicsDefault.
  I want to call this function other file by push the Button.
  In GameViewController i type:</p>
  
  <pre><code>@IBAction func addOneCircle(sender: AnyObject) {
          ACCreateObject.circlePhysicsDefault(ACCreateObject)
  }
  </code></pre>
  
  <p>But i have a issue: '(ACCreateObject).Type' is not convertible to 'ACCreateObject'. How can i call the function?
  What am doing wrong?</p>
  
  <p>Thanks!</p>
  
  <p>ACCreateObject.swift</p>
  
  <pre><code>class ACCreateObject: SKScene {
      func circlePhysicsDefault() {
          var Circle = SKShapeNode(circleOfRadius: 40)
          Circle.position = CGPointMake(500, 500)
          Circle.name = "defaultCircle"
          Circle.strokeColor = SKColor.blackColor()
          Circle.glowWidth = 10.0
          Circle.fillColor = SKColor.yellowColor()
          Circle.physicsBody = SKPhysicsBody(circleOfRadius: 40)
          Circle.physicsBody.dynamic = true
          self.addChild(Circle)
      }
  }
  </code></pre>