title: Material-ui: Warning: Unknown event handler property `onKeyboardFocus`. It will be ignored
body: <p>More detailed trace:</p>
  
  <pre><code>warning.js:33 Warning: Unknown event handler property `onKeyboardFocus`. It will be ignored.
      in div (created by IconMenu)
      in div (created by IconMenu)
      in IconMenu (created by DropdownMenu)
      in div (created by DropdownMenu)
  </code></pre>
  
  <p>I have an IconMenu with a an IconButtonElement prop. For some reason it keeps throwing this warning. Why? What is it?</p>
  
  <p>Sample code that triggers is:</p>
  
  <pre><code>&lt;IconMenu
      iconButtonElement={
          &lt;div&gt;
              &lt;IconButton onClick={this.handleTouchTap}&gt;
                  &lt;div &gt;
                      &lt;img src={require("../../settingsicon.svg")}/&gt;
                  &lt;/div&gt;
              &lt;/IconButton&gt;
          &lt;/div&gt;}
      open={this.state.open}
      anchorOrigin={{horizontal: "right", vertical: "bottom"}}
      targetOrigin={{horizontal: "right", vertical: "top"}}
  &gt;
      &lt;MenuItem
          className={someClass}
          onClick={this.handleLogOutClick}
      &gt;
          &lt;span className={someClass}Hello&lt;/span&gt;
      &lt;/MenuItem&gt;
      &lt;Divider className={someClass}/&gt;
      &lt;MenuItem className={someClass}&gt;
          &lt;span className={someClass}&gt;Goodbye&lt;/span&gt;
      &lt;/MenuItem&gt;
  &lt;/IconMenu&gt;
  </code></pre>
  
  <p>It's a pretty simple example almost copy-pasted from the documentation with a few functions to the menuitems, but nothing that should throw an error such as this. Even when I made a complete barebone example - it still throws the warning. It's a bit ugly to have in the console every time the page loads :) </p>