private void InsertAlignment(int startingPos, int alignment)
{
var charsWritten = _stringBuilder._length - startingPos;
var paddingNeeded = alignment - charsWritten;
if (paddingNeeded > 0)
{
var chars = _stringBuilder._chars;
if (chars.Length - _stringBuilder._length < paddingNeeded)
{
_stringBuilder.Grow(paddingNeeded);
}
chars.Slice(startingPos, charsWritten).CopyTo(chars[(startingPos + paddingNeeded)..]);