| import org.jetbrains.annotations.Contract; |
| import org.jetbrains.annotations.NotNull; |
| import org.jetbrains.annotations.Nullable; |
| |
| abstract class Foo { |
| abstract String getString(); |
| |
| @Contract("null -> null;!null -> !null") |
| public static String delegate(@Nullable String s) { |
| return s == null ? null : s.substring(1); |
| } |
| |
| @Contract("null -> null;!null -> !null") |
| public static String callee(@Nullable Foo element) { |
| return element == null ? null : delegate(element.getString()); |
| } |
| |
| |
| @Contract("!null -> !null") |
| @Nullable public static String delegate2(@Nullable String s) { |
| return s == null ? null : s.substring(1); |
| } |
| |
| @Contract("!null -> !null") |
| @Nullable public static String callee2(@Nullable Object element) { |
| if (element instanceof Foo) return delegate2(((Foo)element).getString()); |
| if (element != null) return element.toString(); |
| return null; |
| } |
| |
| |
| } |