private static void AddOptionalReturnStatement(Block body)
{
if (body.Statements.Count != 1) return;
var stmt = body.FirstStatement as ExpressionStatement;
if (null == stmt) return;
var rs = new ReturnStatement(stmt.LexicalInfo, stmt.Expression, null);
rs.Annotate(OptionalReturnStatementAnnotation);
body.Replace(stmt, rs);
}
