code: func (c *LayerTree) MakeSnapshot(layerId string) (string, error) {
  	var v LayerTreeMakeSnapshotParams
  	v.LayerId = layerId
  	return c.MakeSnapshotWithParams(&v)
  }
docs: // MakeSnapshot - Returns the layer snapshot identifier.
  // layerId - The id of the layer.
  // Returns -  snapshotId - The id of the layer snapshot.