merge method

Implementation

TypographyData merge(TypographyData other) {
  return TypographyData(
    headlineLarge: other.headlineLarge ?? headlineLarge,
    headlineMedium: other.headlineMedium ?? headlineMedium,
    headlineSmall: other.headlineSmall ?? headlineSmall,
    titleLarge: other.titleLarge ?? titleLarge,
    titleMedium: other.titleMedium ?? titleMedium,
    titleSmall: other.titleSmall ?? titleSmall,
    bodyLarge: other.bodyLarge ?? bodyLarge,
    bodyMedium: other.bodyMedium ?? bodyMedium,
    bodySmall: other.bodySmall ?? bodySmall,
    labelLarge: other.labelLarge ?? labelLarge,
    labelMedium: other.labelMedium ?? labelMedium,
    labelSmall: other.labelSmall ?? labelSmall,
  );
}