public DocumentTextWriter(IDocument document, int insertionOffset)
{
InsertionOffset = insertionOffset;
if (document == null)
throw new ArgumentNullException("document");
this.document = document;
var line = document.GetLineByOffset(insertionOffset);
if (line.DelimiterLength == 0)
line = line.PreviousLine;
if (line != null)
NewLine = document.GetText(line.EndOffset, line.DelimiterLength);
}