merge method
Implementation
ElTextThemeData merge([ElTextThemeData? other]) {
if (other == null) return this;
return copyWith(
textStyle: other.textStyle,
regularStyle: other.regularStyle,
secondaryStyle: other.secondaryStyle,
placeholderStyle: other.placeholderStyle,
h1Style: other.h1Style,
h2Style: other.h2Style,
h3Style: other.h3Style,
h4Style: other.h4Style,
h5Style: other.h5Style,
h6Style: other.h6Style,
);
}