static PrimitiveExpression CreateFormatString(RefactoringContext context, PrimitiveExpression pExpr, int argumentNumber)
{
var start = context.GetOffset(pExpr.StartLocation);
var end = context.GetOffset(pExpr.EndLocation);
return(new PrimitiveExpression("", context.GetText(start, context.SelectionStart - start) + "{" + argumentNumber + "}" + context.GetText(context.SelectionEnd, end - context.SelectionEnd)));
}