A custom legend key function that displays only an arrow (edge) without nodes.
This is appropriate for edge-specific legends where nodes are not relevant.
Usage
draw_key_dag_edge(data, params, size)
Arguments
- data
A data frame containing aesthetic information for the legend key
- params
Additional parameters (not currently used)
- size
Legend key size (not currently used)
Value
A grob object for the legend key
