SwingModifierUnreferencedReceiver
Reports a SwingModifier factory whose body never reaches the chain it was given.
A factory extension is handed the receiver so a caller's own chain rides through it. A body that restarts the chain from SwingModifier itself, rather than from the receiver, returns a chain built from nothing and drops everything the caller had declared.
Nothing short of resolving types tells a call that takes the receiver implicitly apart from a plain function call, so a body that delegates that way - listener(...), binding(...), property(...), which is how most factories in this library are written - is passed over. Only a body whose answer is a chain rooted at SwingModifier itself, taking the receiver in nowhere along it, is reported: that is the one shape a fresh chain and a dropped receiver can be told apart in without resolving anything.