Provides built-in ranking and transformers to apply to the current
workspace. For instance for nodes, ranking can be the degree of the
node or a numerical value like an 'age' or 'duration'. By default, the
RankingModel have 'Degree', 'InDegree', 'OutDegree' and
one ranking per numerical attribute. Ranking exists for both nodes and
edges and these are called element types.
See the org.gephi.ranking.spi package to know how to
implement new ranking or transformer builders.