Example:

class A {
  @WireVariable private MyClass var;
}

class B extends A {
  @WireVariable private MyClass var;
}

When using wiring variables for B, field var in superclass A will not be wired (will be null). This is documented in Reflections.forFields() method which is used in Selectors.Wirer.wireVariables(). But such a solution is counter-object-oriented - subclass B it breaks class's A contract by mere declaration of a field with the same name. That way, class A depends on its subclasses and not the other way around - class A works only if the subclass does not wire a field with the same name. Furthermore, it requires the programmer to know about class's A private member when implementing subclass B, thus breaking class's A encapsulation.

All fields annotated with @WireVariable should be wired in the whole class hierarchy.