f strings defining valid turtles-own
variables that are taken as output measurements (e.g. c("who", "pxcor",
"pycor", "color"))</p></dd>
    <dt><code>metrics.patches</code></dt><dd><p>vector of strings defining valid patches-own
variables that are taken as output measurements (e.g. c("pxcor",
"pycor", "pcolor"))</p></dd>
    <dt><code>metrics.links</code></dt><dd><p>vector of strings defining valid links-own variables
that are taken as output measurements (e.g. c("end1", "end2"))</p></dd>
    <dt><code>var