title: Ag grid to check if column is visible or not
body: <p>I'm trying to hide/Show columns in Ag grid.</p>
  
  <p>Below is my code for hiding/showing columns</p>
  
  <pre><code> this.gridOptions.columnApi.setColumnsVisible(["Col1", "Col2"], true);
  
   this.gridOptions.columnApi.setColumnsVisible(["Col3", "Col4"], false);
  </code></pre>
  
  <p>How do i find, if the columns are already hidden or visible ? based on the current state of the columns, i need to execute the above code. Please help</p>