void (@NotNull Language language, @NotNull PsiReferenceContributor instance) { PsiReferenceRegistrarImpl registrar = myRegistrars.get(language); if (registrar != null) { registerContributedReferenceProviders(registrar, instance); } for (Language dialect : language.getTransitiveDialects()) { registrar = myRegistrars.get(dialect); if (registrar != null) { registerContributedReferenceProviders(registrar, instance); } } }