@NotNull
  Content createContent(@NotNull @NonNls String contentId,
                        @NotNull JComponent component,
                        @NotNull @Nls String displayName,
                        @Nullable Icon icon,
                        @Nullable JComponent toFocus);
@NotNull
  Content createContent(@NotNull @NonNls String contentId,
                        @NotNull JComponent component,
                        @NotNull @Nls String displayName,
                        @Nullable Icon icon,
                        @Nullable JComponent toFocus)