Reports overloaded methods that take functional interfaces with conflicting abstract method signatures. Such overloads introduce ambiguity and require callers to cast lambdas to a specific type or specify lambda parameter types explicitly. It is preferable to give the overloaded methods different names to eliminate ambiguity.

Example:

interface MyExecutor {
  void execute(Supplier supplier);
  void execute(Callable callable);
}

Here, Supplier and Callable are functional interfaces whose single abstract methods don’t take any parameters and return a non-void value. As a result, the type of the lambda can’t be inferred at the call site unless an explicit cast is used.