agent_set: Create an agent set reporter
In bergant/nlexperiment: Exploration of NetLogo Agent Based Models

Create an agent set reporter to set agent reporters in 'nl_experiment' or 'nl_set_agent_reports'

1	agent_set(vars, agents)

`vars`	A string or vector/list of strings with the variable names of the agent(s).
`agentset`	A string specifying the agent or agentset to be queried.

experiment <- nl_experiment(
  model_file = "models/Sample models/Networks/Preferential attachment.nlogo",
  iterations = 30,
  export_view = TRUE,
  agents_after = list(
    vertices = agent_set(c("who", "xcor", "ycor"), "turtles"),
    edges = agent_set(vars = c(e1 = "[who] of end1", e2 ="[who] of end2"), agents = "links")
  )
)