T- This type parameter specifies the type of signal data which can be accepted by the signalable object.
public interface Signalable<T>
Note that objects implementing this interface must not attempt to override the default 'equals' method since this is used as an identity test within the reactor core.
signalId- This is a handle on a signal event object which may be used to identify the source of the signal being raised.
data- This is the signal data object which is passed as a parameter to the signal event. It should be treated as an immutable object and no attempt should be made to change the state of this object within the callback.