TextRange range= getTextRange(); fContent= buffer.getContent(range.getOffset(), range.getLength());
fContent= computeContent(buffer);
	public void perform(TextBuffer buffer) throws CoreException {		TextRange range= getTextRange();		fContent= buffer.getContent(range.getOffset(), range.getLength());		TextRange targetRange= fTarget.getTextRange();		if (++fCounter == 2 && !targetRange.isDeleted()) {			try {				buffer.replace(targetRange, fContent);			} finally {				clearContent();			}		}	}