Function createRef

createRef(ref): LayerReference | SublayerReference | undefined
Creates a LayerReference or SublayerReference from various input types.
Parameters
- ref:
      | string
      | number
      | Layer
      | SublayerLike
      | LayerReference
      | SublayerReference
  The reference, which can be a string, number, LayerReference, SublayerReference, Layer, or SublayerLike.
Returns LayerReference | SublayerReference | undefined
A LayerReference or SublayerReference object.