boolean (@NotNull AnActionEvent event) { Project project = event.getProject(); if (project == null || project.isDisposed()) return false; if (getVcsHelper(project) == null) return false; AbstractVcs vcs = getVcs(project, event.getData(VcsDataKeys.VCS)); if (vcs == null) return false; VcsHistoryProvider vcsHistoryProvider = vcs.getVcsHistoryProvider(); if (!(vcsHistoryProvider instanceof VcsHistoryProviderEx)) return false; return true; }