merge method

Implementation

TooltipThemeData merge(TooltipThemeData? style) {
  if (style == null) return this;
  return TooltipThemeData(
    decoration: style.decoration ?? decoration,
    height: style.height ?? height,
    margin: style.margin ?? margin,
    padding: style.padding ?? padding,
    preferBelow: style.preferBelow ?? preferBelow,
    showDuration: style.showDuration ?? showDuration,
    textStyle: style.textStyle ?? textStyle,
    verticalOffset: style.verticalOffset ?? verticalOffset,
    waitDuration: style.waitDuration ?? waitDuration,
  );
}