Attempts to activate the current {#possibility} (given that it has already been activated) @return [void]
Pushes a new {DependencyState}. If the {#specification_provider} says to {SpecificationProvider#allow_missing?} that particular requirement, and there are no possibilities for that requirement, then ‘state` is not pushed, and the node in {#activated} is removed, and we continue resolving the remaining requirements. @param [DependencyState] state @return [void]