Use to generate customized CodeText for Code128 barcode.
[Sample]
Code128CodeBuilder builder = new Code128CodeBuilder(Code128Set.A);
String codeText = builder.Append("1234").Switch(Code128Set.B).Append("5678").toString();
BarCodeBuilder b = new BarCodeBuilder(Symbology.CODE128, codeText);
b.setCode128Set(Code128Set.Customized);
String file = "code128.png";
b.save(file);