title: Whether sparql federated query supports query from multi-graph?
body: <p>I want to use <a href="https://www.w3.org/TR/sparql11-federated-query/#service" rel="nofollow noreferrer">sparql federated query</a> to select from multi-graph, but find errors:</p>
  <pre><code>Parse error: Encountered &quot; &quot;from&quot; &quot;FROM &quot;&quot; at line 5, column 5.
  </code></pre>
  <p>sparql:</p>
  <pre><code>SELECT *
  WHERE {
    SERVICE &lt;sparql endpoint&gt; {
      SELECT *
      FROM &lt;graph 1&gt;
      FROM &lt;graph 2&gt;
      FROM &lt;graph 3&gt;
      WHERE { ... }
    }
  }
  </code></pre>
  <p>I want to know whether sparql federated query supports query from multi-graph.</p>
  <p>Best regards</p>