title: How to define starting state of queueing model in r simmer?
body: <p>Here's the standard bank counter problem to illustrate my question:</p>
  
  <blockquote>
    <p>Consider a simple bank with customers arriving at random. Customers
    are to be served at one of two counters, taking a random time for
    service at each. Also, assume that waiting customers form a single
    FIFO queue.</p>
  </blockquote>
  
  <p>Here's the complication:</p>
  
  <blockquote>
    <p>Suppose we are interested in modeling this system starting noon of a
    particular day instead of at the start of the day. At noon, both
    counters are occupied and there is already a queue of 4 customers. </p>
  </blockquote>
  
  <p>Is there a way to build in this starting state in R simmer?</p>
  
  <p>Here's the code I already have:</p>
  
  <pre><code>library(simmer)
  
  set.seed(1234)
  
  customer &lt;- 
    trajectory("Customer's path") %&gt;%
    log_("Here I am") %&gt;% 
    set_attribute("start_time", function() {now(bank)}) %&gt;% 
    seize("counter") %&gt;% 
    log_(function() {paste("Waited: ", now(bank) - get_attribute(bank, "start_time"))}) %&gt;% 
    timeout(function() {rexp(1, 1/12)}) %&gt;% 
    release("counter") %&gt;% 
    log_(function() {paste("Finished: ", now(bank))})
  
  bank &lt;- 
    simmer("bank") %&gt;% 
    add_resource("counter", 2) %&gt;% 
    add_generator("Customer", customer, function() sample(1:15,1))
  
  bank %&gt;% run(until = 300)
  </code></pre>