toJson method
NOTE: parent is excluded from JSON output on purpose to prevent cyclic
traversal of the object graph (parent -> child -> parent -> ...), which
causes stack overflows. Only downward links (children) are serialized.
Parent links are restored after fromJson runs _rebuildParentReferences().
See: @JsonKey(includeFromJson: false, includeToJson: false) on parent (including its getter) and DartBlockEnvironment.fromJson.
Implementation
Map<String, dynamic> toJson() => _$DartBlockEnvironmentToJson(this);