| An equals method compares non-corresponding fields from itself and the other | |
| instance: | |
| ```java | |
| class Frobnicator { | |
| private int a; | |
| private int b; | |
| @Override | |
| public boolean equals(@Nullable Object other) { | |
| if (!(other instanceof Frobnicator)) { | |
| return false; | |
| } | |
| Frobnicator that = (Frobnicator) other; | |
| return a == that.a && b == that.a; // BUG: should be b == that.b | |
| } | |
| } | |
| ``` |