paperSizeForChars function
Implementation
KeckPaperSize paperSizeForChars(int chars, String fallback) {
if (chars == KeckPaperSize.mm58.defaultCharCount) return KeckPaperSize.mm58;
if (chars == KeckPaperSize.mm80.defaultCharCount) return KeckPaperSize.mm80;
return fallback == 'mm80' ? KeckPaperSize.mm80 : KeckPaperSize.mm58;
}