For example when I have builder like:

Builder builder = new IdentityConfigurationBuilder()
  .named("default")
    .store();
  .named("default")
  .store();

The second call to method named("default") didn't return me the previously created instance of NamedIdentityConfigurationBuilder, but it always create new NamedIdentityConfigurationBuilder and return this new instance.

It's not good as it doesn't allow me to return already existing instance of named builder and change it (For example if builder is partially initialized from XML, but I need to add some stuff programmatically to it).

Also it's error prone as it could end with more instances if IdentityConfiguration with same name.