@AutoValue classes are intended to be closed, with a single implementation
with known semantics. Implementing them by hand is extremely dangerous.
Here are some common cases where we have seen code that extends @AutoValue
classes and recommendations for what to do instead:
Overriding the getters to return given values. This should usually be
replaced by creating an instance of the @AutoValue class with those
values.
Having the @AutoValue.Builder class extend the @AutoValue class so it
inherits the abstract getters. This is wrong since the Builder doesn’t
satisfy the contract of its superclass and is better implemented either by
repeating the methods or by having both the @AutoValue class and the
Builder implement a common interface with these getters.
In other cases of extending the @AutoValue class and implementing its
abstract methods, it would be more correct to have the @AutoValue class
and the other class have a common supertype.
Suppress false positives by adding the suppression annotation @SuppressWarnings("ExtendsAutoValue") to the enclosing element.