Uncaught Error: Invariant Violation: processUpdates(): Unable to find child 2 of element. This probably means the DOM was unexpectedly mutated ...

/** @jsx React.DOM */

React = require('react');

var _ = require("underscore");

var testComp = React.createClass({

  getInitialState: function () {
    return {
      collapsed: false
    };
  },

  handleCollapseClick: function(){
    this.setState({collapsed: !this.state.collapsed});
  },

  render: function() {

    var rows = [
      <tr onClick={this.handleCollapseClick}><th>Header 1</th><th>Header 2</th><th>Header 3</th></tr>
    ];

    if(!this.state.collapsed){
      rows.push(<tr><th>Row1 1</th><th>Row1 2</th><th>Row1 3</th></tr>);
    }

    rows.push(<tr><th>Footer 1</th><th>Footer 2</th><th>Footer 3</th></tr>);

    return  <div>
                <table>
                    {rows}
                </table>
            </div>
  }

});

module.exports = testComp

if(!this.state.collapsed){
  rows.push(<tr><th>Row1 1</th><th>Row1 2</th><th>Row1 3</th></tr>);
}else{
  rows.push(<tr><th>Row2 1</th><th>Row2 2</th><th>Row2 3</th></tr>);
}