private Statement ParseReturnStatement()
{
var returnKeyword = MatchToken(TokenKind.ReturnKeyword);
// Cheat
var keywordLine = source.LineIndexOf(returnKeyword.Location.Span.Start);
var currentLine = source.LineIndexOf(PeekToken(0).Location.Span.Start);
var isEoF = Current == TokenKind.EoF;
var isCloseBrace = Current == TokenKind.CloseBrace;
var sameLine = keywordLine == currentLine;
var expression = sameLine && !isEoF && !isCloseBrace ? ParseExpression() : null;
return new ReturnStatement(syntaxTree, returnKeyword, expression);
}