toJson method
Implementation
Map<String, dynamic> toJson() {
return {
'axis': axis.toJson(),
if (sourceNodeId != null) 'sourceNodeId': sourceNodeId!.toJson(),
if (startOffset != null) 'startOffset': startOffset,
if (endOffset != null) 'endOffset': endOffset,
if (subjectNodeId != null) 'subjectNodeId': subjectNodeId!.toJson(),
};
}