void (@NotNull FilePath filePath, @NotNull VcsFileRevision older, @NotNull VcsFileRevision newer) { if (!filePath.isDirectory()) { VcsHistoryUtil.showDifferencesInBackground(myProject, filePath, older, newer); } else if (older.equals(VcsFileRevision.NULL)) { T right = (T)newer; showAffectedChanges(filePath, right); } else if (newer instanceof CurrentRevision) { T left = (T)older; showChangesBetweenRevisions(filePath, left, null); } else { T left = (T)older; T right = (T)newer; showChangesBetweenRevisions(filePath, left, right); } }