old_contents: import React from 'react'
  import PropTypes from 'prop-types'
  import FakeCourse from './fake-course'
  
  export default function MissingCourse(props) {
  	return (
  		<FakeCourse
  			title={`Cannot load course ${props.clbid}`}
  			details={String(props.error)}
  			className={`missing ${props.className}`}
  		/>
  	)
  }
  
  MissingCourse.propTypes = {
  	className: PropTypes.string,
  	clbid: PropTypes.number.isRequired,
  	error: PropTypes.oneOfType([PropTypes.string, PropTypes.instanceOf(Error)])
  		.isRequired,
  }
  
new_contents: // @flow
  
  import React from 'react'
  import FakeCourse from './fake-course'
  
  type Props = {
  	+className?: string,
  	+clbid: string,
  	+error: string | Error,
  }
  
  export default function MissingCourse(props: Props) {
  	return (
  		<FakeCourse
  			title={`Cannot load course ${props.clbid}`}
  			details={String(props.error)}
  			className={`missing ${props.className || ''}`}
  		/>
  	)
  }
  
subject: convert MissingCourse to flow