title: How to create a simple Tuple class in Dart?
body: <p>Why I cannot initialize this class?</p>
  <pre><code>class ChangeThis&lt;T1, T2&gt; {
    final T1 item1;
    final T2 item2;
  
    ChangeThis({
      this.item1,
      this.item2,
    });
  }
  
  int main() {
    ChangeThis&lt;bool, int&gt; changeThis = new ChangeThis&lt;bool, int&gt;(true, 0);
  }
  </code></pre>
  <p>I followed this answer: <a href="https://stackoverflow.com/a/63060545">https://stackoverflow.com/a/63060545</a>, but I get:</p>
  <pre><code>Too many positional arguments: 0 allowed, but 2 found.
    ChangeThis&lt;bool, int&gt; changeThis = new ChangeThis&lt;bool, int&gt;(true, 0);
  </code></pre>