text: import React, { Component } from 'react';
  import PropTypes from 'prop-types';
  
  class Login extends Component {
    static propTypes = {
      authenticate: PropTypes.func,
      logout: PropTypes.func,
      uid: PropTypes.string,
    };
    static defaultProps = {
      authenticate: () => {},
      logout: () => {},
      uid: '',
    };
  
    render() {
      let headerText = 'Login';
      let actions = (
        <button className="btn-login github" onClick={() => this.props.authenticate('Github')}>Log In With Github</button>
      );
  
      if (this.props.uid) {
        headerText = 'You are logged in';
        actions = (
          <button className="btn-logout" onClick={this.props.logout}>Log Out</button>
        );
      }
  
      return (
        <div className="App App-login">
          <h1 className="header-login">{headerText}</h1>
          {actions}
        </div>
      );
    }
  }
  
  export default Login;
  