old_contents: import React from 'react';
  import { connect } from 'react-redux';
  
  import { fetchCourses } from 'actions/courses';
  import CourseContainer from 'components/CourseContainer';
  
  const CourseContainerRoot = (props) => {
    const onFetchButtonClick = () => {
      props.dispatch(
        fetchCourses('https://www.udacity.com/public-api/v0/courses')
      );
    };
  
    return (
      <div>
        <button onClick={onFetchButtonClick}>
          Fetch
        </button>
        <br /><br />
        <CourseContainer data={props.courses} />
      </div>
    );
  };
  
  export default connect(
    state => ({ courses: state.courses })
  )(CourseContainerRoot);
  
new_contents: import React from 'react';
  import { connect } from 'react-redux';
  
  import { fetchCourses } from 'actions/courses';
  import CourseContainer from 'components/CourseContainer';
  
  const CourseContainerRoot = props => {
    const onFetchButtonClick = () => {
      props.dispatch(
        fetchCourses('https://www.udacity.com/public-api/v0/courses')
      );
    };
  
    return (
      <div>
        <button onClick={onFetchButtonClick}>
          Fetch
        </button>
        <br /><br />
        <CourseContainer data={props.courses} />
      </div>
    );
  };
  
  export default connect(
    state => ({ courses: state.courses })
  )(CourseContainerRoot);
  
subject: Remove not needed brackets parentheses