This issue is raised when abstract methods are found outside of an abstract class. This would result in a fatal runtime error.
To fix this, either implement the abstract methods or put them in an abstract class.
class AbstractRule
{
abstract public function run(): void;
}
Make the class abstract:
abstract class AbstractRule
{
abstract public function run(): void;
}
Or, remove the abstract modifier from the method:
class AbstractRule
{
public function run(): void;
}