/// <summary>
 /// Writes a <see cref="TextLayoutCommandType.ChangeSourceString"/> command to the current position in the stream.
 /// </summary>
 /// <param name="command">The command to write to the stream.</param>
 public void WriteChangeSourceString(TextLayoutSourceStringCommand command)
 {
     stream.Reserve(sizeof(TextLayoutSourceStringCommand));
     *(TextLayoutSourceStringCommand *)stream.Data = command;
     *(TextLayoutCommandType *)stream.Data         = TextLayoutCommandType.ChangeSourceString;
     stream.FinalizeObject(sizeof(TextLayoutSourceStringCommand));
 }
 /// <summary>
 /// Writes a <see cref="TextLayoutCommandType.ChangeSourceString"/> command to the current position in the stream.
 /// </summary>
 /// <param name="command">The command to write to the stream.</param>
 public void WriteChangeSourceString(TextLayoutSourceStringCommand command)
 {
     stream.Reserve(sizeof(TextLayoutSourceStringCommand));
     *(TextLayoutSourceStringCommand*)stream.Data = command;
     *(TextLayoutCommandType*)stream.Data = TextLayoutCommandType.ChangeSourceString;
     stream.FinalizeObject(sizeof(TextLayoutSourceStringCommand));
 }