copyFrom method
Implementation
void copyFrom(IDialogTheme theme){
if(isNullOrEmpty(accentColor)) accentColor = theme.accentColor;
if(isNullOrEmpty(backgroundColor)) backgroundColor = theme.backgroundColor;
if(isNullOrEmpty(textOnAccentColor)) textOnAccentColor = theme.textOnAccentColor;
if(isNullOrEmpty(textOnBackgroundColor)) textOnBackgroundColor = theme.textOnBackgroundColor;
if(isNullOrEmpty(textHighlightColor)) textHighlightColor = theme.textHighlightColor;
}