{@inheritDoc} <p> Activation of this method decrements the active count associated with the given keyed pool and attempts to destroy <code>obj.</code>
@param key pool key @param obj instance to invalidate
@throws Exception if an exception occurs destroying the object @throws IllegalStateException if obj does not belong to the pool under the given key
See Implementation
{@inheritDoc} <p> Activation of this method decrements the active count associated with the given keyed pool and attempts to destroy <code>obj.</code>
@param key pool key @param obj instance to invalidate
@throws Exception if an exception occurs destroying the object @throws IllegalStateException if obj does not belong to the pool under the given key