private static SpannableStringBuilder AppendSpan(this SpannableStringBuilder mutableString, ISpan span)
{
switch (span)
{
case TextSpan textSpan:
mutableString.AppendNormalText(textSpan);
break;
case ProjectSpan projectSpan:
mutableString.AppendProjectText(projectSpan);
break;
case TagSpan tagSpan:
mutableString.AppendTagText(tagSpan);
break;
}
return(mutableString);
}