toJson method
Implementation
core.Map<core.String, core.dynamic> toJson() => {
if (filter != null) 'filter': filter!,
if (summaryFieldEnd != null) 'summaryFieldEnd': summaryFieldEnd!,
if (summaryFieldStart != null) 'summaryFieldStart': summaryFieldStart!,
if (summaryFields != null) 'summaryFields': summaryFields!,
};