title: Instantiation of a class doesn't work (Chisel/Scala)
body: <p>I got the following error:</p>
  <pre><code>java.lang.IllegalArgumentException: requirement failed: must be inside Builder context
  </code></pre>
  <p>issue when I write this on the terminal : sbt run</p>
  <p>This is my code:</p>
  <pre class="lang-scala prettyprint-override"><code>import chisel3._
  
  class combinedTausworthe extends Module {
    val io = IO(new Bundle {})
    val seed1 = RegInit(322769304.U(32.W))
    val seed2 = RegInit(424235419.U(32.W))
    val seed3 = RegInit(212119443.U(32.W))
    var result = 0.U
  
    var b = ((seed1 &lt;&lt; 13)(31, 0) ^ seed1)
    seed1 := ((seed1 &amp; 4294967294L.U) &lt;&lt; 12)(31, 0) ^ b
    b := ((seed2 &lt;&lt; 2)(31, 0) ^ seed2) &gt;&gt; 25
    seed2 := ((seed2 &amp; 4294967294L.U) &lt;&lt; 4)(31, 0) ^ b
    b := ((seed3 &lt;&lt; 3)(31, 0) ^ seed3) &gt;&gt; 11
    seed3 := ((seed3 &amp; 4294967294L.U) &lt;&lt; 17)(31, 0) ^ b
  
    result := (seed1 ^ seed2 ^ seed3)
    println(result)
  
  }
  
  object Main extends App {
    val variable = Module(new combinedTausworthe())
  }
  </code></pre>