It is indeed a performance penalty, but is required to avoid conflicts with built-in properties (such as __proto__). For modern browsers we could probably use Map nowadays.
You should bring this to gwt-contrib!
You received this message because you are subscribed to the Google Groups "GWT Users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to firstname.lastname@example.org.
To post to this group, send email to email@example.com.
Visit this group at https://groups.google.com/group/google-web-toolkit.
For more options, visit https://groups.google.com/d/optout.