toJson method
Implementation
Map<String, dynamic> toJson() => {
"hr": hr,
"br": br,
"bold": bold,
"bmpBase64": bmpBase64,
"center": center,
"text1": text1,
"label1": label1,
"text2": text2,
"label2": label2,
"text3": text3,
"label3": label3,
"charsPerLine": charsPerLine,
}..removeWhere((key, value) => value == null);