Snapshot constructor Null safety
Implementation
Snapshot(this.id, {this.render, this.layer, this.image}) {
if (render != null) {
type = SnapshotType.render;
} else if (layer != null) {
type = SnapshotType.layer;
} else if (image != null) {
type = SnapshotType.image;
} else {
throw Exception('Snapshot: Incorrect construction of Snapshot');
}
}