title: Unable to get visible texteditor in other viewcolumn
body: <p>I'm trying to open the active file in a new viewcolumn, and fold a tag. The folding commands work fine in <code>activeTextEditor</code>:</p>
  
  <pre class="lang-ts prettyprint-override"><code>// Fold based on linenumber
  let range = editor.document.lineAt(lineNumber).range;
  editor.selection = new vscode.Selection(range.start, range.end);
  editor.revealRange(range);
  commands.executeCommand('editor.fold');
  </code></pre>
  
  <p>Now I would like to do the same in a newly opened file:</p>
  
  <pre class="lang-ts prettyprint-override"><code>// Open the same file in a new column
  // at this time editor.ViewColum is One
  commands.executeCommand('vscode.open', Uri.file(editor.document.fileName), ViewColumn.Two);
  
  // Try to get that editor
  let newEditor = vscode.window.visibleTextEditors.find(x=&gt; x.viewColumn===viewColumn.Two &amp;&amp; x.document.fileName===fileName)
  </code></pre>
  
  <p>The problem is that <code>newEditor</code> is not found, becouse the newly opened document has <code>ViewColumn</code> <code>undefined</code>.</p>
  
  <p>Any idea how to solve this?</p>
  
  <p>Thanks</p>