Observed this on react@16.0.0-beta.5

```js
import React from 'react';
import { renderToString } from 'react-dom/server';

const B = () => 'b';

console.log(renderToString(<div>{'a'}<B />{'c'}</div>));
```

This renders as `<div data-reactroot="">a<!-- -->bc</div>`. If you try to hydrate this you'll get the error: Text content did not match. Server: "bc" Client: "b".
super();
            this.state = {value: true};
          }
          handleChange(event) {
            if (this.props.onChange) {
              this.props.onChange(event);
            }
            this.setState({value: event.target.checked});
          }
          render() {
            return (
              <input
                type="checkbox"
                checked={this.state.value}
                onChange={this.handleChange.bind(this)}
              />
            );
          }
        };
        ControlledSelect = class extends React.Component {
          constructor() {