private static SyntaxTreeIndex ReadFrom(ObjectReader reader, VersionStamp version) { var identifierInfo = IdentifierInfo.ReadFrom(reader); var contextInfo = ContextInfo.ReadFrom(reader); var declarationInfo = DeclarationInfo.ReadFrom(reader); if (identifierInfo == null || contextInfo == null || declarationInfo == null) { return(null); } return(new SyntaxTreeIndex( version, identifierInfo.Value, contextInfo.Value, declarationInfo.Value)); }