toJson method
Implementation
core.Map<core.String, core.dynamic> toJson() => {
if (config != null) 'config': config!,
if (expr != null) 'expr': expr!,
if (exprOptions != null) 'exprOptions': exprOptions!,
if (versionedExpr != null) 'versionedExpr': versionedExpr!,
};