Spine skeleton help with slots

Two basic questions about spine:

1- How to hide/show a slot with lua.

2- How to change an image for other one inside a slot, example:

    (o) Slot

        X Image1

        - Image2

I answer myself:

1-

   local mySlot=skeleton:findSlot(“hair”)
   mySlot.a=0

2

   skeleton:setAttachment(“hair”, “hair_2”);   works
   skeleton.setAttachment(“slotName”, “attachmentName”);   doesn’t work(oficial documentation)

I answer myself:

1-

   local mySlot=skeleton:findSlot(“hair”)
   mySlot.a=0

2

   skeleton:setAttachment(“hair”, “hair_2”);   works
   skeleton.setAttachment(“slotName”, “attachmentName”);   doesn’t work(oficial documentation)