Implementation of Transformer defined in RankingAPI.

Use these transformers to:

• RenderableColorTransformer: Color nodes or edges. Input NodeData or EdgeData elements.
• RenderableSizerTransformer: Size nodes or edges. Input NodeData or EdgeData elements.
• LabelColorTransformer: Color node or edge labels. Input NodeData or EdgeData elements.
• LabelSizeTransformer: Size node or edges labels. Input NodeData or EdgeData elements.