Extract Column Names for targets in Drake Plan

Given a drake::drake_plan(), extract the column names of each target, and store it in a new column.

extract_column_names(
  plan,
  cache,
  group = NULL,
  clusters = NULL,
  colname_out = "target_column_list",
  ...
)

Arguments

group	Optional character scalar, name of the column used to group nodes into columns. All the columns names of your original `drake` plan are choices. The other choices (such as `"status"`) are column names in the `nodes` . To group nodes into clusters in the graph, you must also supply the `clusters` argument.
clusters	Optional character vector of values to cluster on. These values must be elements of the column of the `nodes` data frame that you specify in the `group` argument to `drake_graph_info()`.
colname_out	the name given to the list-column containing each target's columns