const buttonsInstance = (

<div>

<ButtonToolbar>

<Button bsStyle="primary" bsSize="large">Large button</Button>

<Button bsSize="large">Large button</Button>

</ButtonToolbar>

<ButtonToolbar>

<Button bsStyle="primary">Default button</Button>

<Button>Default button</Button>

</ButtonToolbar>

<ButtonToolbar>

<Button bsStyle="primary" bsSize="small">Small button</Button>

<Button bsSize="small">Small button</Button>

</ButtonToolbar>

<ButtonToolbar>

<Button bsStyle="primary" bsSize="xsmall">Extra small button</Button>

<Button bsSize="xsmall">Extra small button</Button>

</ButtonToolbar>

</div>

);

ReactDOM.render(buttonsInstance, mountNode);