text: import React from 'react';
  import PropTypes from 'prop-types';
  import { connect } from 'react-redux';
  import { authActions } from 'firebase-sagas';
  import { PageHeader, Button, Glyphicon } from 'react-bootstrap';
  
  const Header = props => (
    <PageHeader>
        firebase-sagas <small>Example</small>
      {props.authenticated && <Button bsStyle="link" onClick={props.signOut}>
        <Glyphicon glyph="log-out" />
        </Button>}
    </PageHeader>
    );
  
  Header.propTypes = {
    authenticated: PropTypes.bool.isRequired,
    signOut: PropTypes.func.isRequired,
  };
  
  const mapStateToProps = ({ auth }) => ({ authenticated: auth.authenticated });
  
  export default connect(mapStateToProps, authActions)(Header);
  