def possibility_versions(requirement, activated)
      activated.vertices.values.flat_map do |vertex|

        next unless vertex.payload

        next unless vertex.name == requirement.name

        if vertex.payload.respond_to?(:possibilities)
          vertex.payload.possibilities.map(&:version)
        else
          vertex.payload.version
        end
      end.compact
    end
def possibility_versions(requirement, activated)
      activated.vertices.values.flat_map do |vertex|

        next unless vertex.payload

        next unless vertex.name == requirement.name

        if vertex.payload.respond_to?(:possibilities)
          vertex.payload.possibilities.map(&:version)
        else
          vertex.payload.version
        end
      end.compact
    end
Searches the current dependency graph to find previously activated
 requirements for the current artifact.

 @param [Object] requirement
 @param [DependencyGraph] activated the current dependency graph in the
   resolution process.
 @return [Array<Semverse::Version> the list of currently activated versions
 of this requirement