title: Graphql variable type error expecting unknown types "equals" and "in"
body: <p>I am getting an error with Graphql type definition.</p>
  <p>This is part of my query:</p>
  <pre><code>query MyQuery($myFirstVariable: NonEmptyString!, $mySecondVariable: [NonEmptyString!]!) {
    myBooks(
      input: {
        filter: {
          myFirstVariable: { equals: $myFirstVariable }
          mySecondVariable: { in: $mySecondVariable }
        }
        // ...
      }
    ) {
    //...
  }
  </code></pre>
  <p>Variables:</p>
  <pre><code>{
      &quot;myFirstVariable&quot;: &quot;string&quot;,
      &quot;mySecondVariable&quot;: [&quot;array of string&quot;]
  }
  </code></pre>
  <p>Errors:</p>
  <p>&quot;Variable &quot;$myFirstVariable&quot; of type &quot;NonEmptyString!&quot; used in position expecting type &quot;equals!&quot;</p>
  <p>&quot;Variable &quot;$mySecondVariable&quot; of type &quot;[NonEmptyString!]!&quot; used in position expecting type &quot;in!&quot;</p>