docs: def setCurrentLayer(self, layer):
          """
          Sets the current layer for this scene to the inputed layer.
          
          :param      layer | <XNodeLayer> || None
          """
          if self._currentLayer == layer:
              return False
          
          old = self._currentLayer
          self._currentLayer = layer
          
          if old is not None:
              old.sync()
          if layer is not None:
              layer.sync()
          
          self.selectionFinished.emit()
          self.invalidate()
          
          return True