toJson method Null safety

Implementation

Map<String, dynamic> toJson() {
  final Map<String, dynamic> data = <String, dynamic>{};
  data['0'] = _d0;
  data['1'] = _d1;
  data['2'] = _d2;
  data['3'] = _d3;
  data['4'] = _d4;
  data['5'] = _d5;
  data['6'] = _d6;
  data['7'] = _d7;
  data['8'] = _d8;
  data['9'] = _d9;
  data['10'] = _d10;
  data['12'] = _d12;
  data['16'] = _d16;
  data['20'] = _d20;
  data['24'] = _d24;
  data['32'] = _d32;
  data['40'] = _d40;
  data['48'] = _d48;
  data['56'] = _d56;
  data['64'] = _d64;
  data['72'] = _d72;
  data['80'] = _d80;
  data['96'] = _d96;
  data['0.5'] = _d05;
  data['1.5'] = _d15;
  data['2.5'] = _d25;
  data['3.5'] = _d35;
  return data;
}