| graphical element       | `geom` used                 | argument for further modification |
| :---------------------- | :-------------------------- | :-------------------------------- |
| raw data                | `ggplot2::geom_point()`     | `point.args`                      |
| error bars              | `ggplot2::geom_errorbarh()` | `errorbar.args`                   |
| centrality measure line | `ggplot2::geom_vline()`     | `centrality.line.args`            |
