old_contents: // @flow
  
  /**
   * CSS to style the selection psuedo-element.
   *
   * @example
   * // Styles as object usage
   * const styles = {
   *   ...placeholder({'color': 'blue'})
   * }
   *
   * // styled-components usage
   * const div = styled.input`
   *    ${placeholder({'color': 'blue'})}
   * `
   *
   * // CSS as JS Output
   *
   * 'input': {
   *   '&:-moz-placeholder': {
   *     'color': 'blue',
   *   },
   *   '&:-ms-input-placeholder': {
   *     'color': 'blue',
   *   },
   *   '&::-moz-placeholder': {
   *     'color': 'blue',
   *   },
   *   '&::-webkit-input-placeholder': {
   *     'color': 'blue',
   *   },
   * },
   */
  
  function placeholder(styles: Object, parent?: string = '&'): Object {
    return {
      [`${parent}::-webkit-input-placeholder`]: {
        ...styles,
      },
      [`${parent}:-moz-placeholder`]: {
        ...styles,
      },
      [`${parent}::-moz-placeholder`]: {
        ...styles,
      },
      [`${parent}:-ms-input-placeholder`]: {
        ...styles,
      },
    }
  }
  
  export default placeholder
  
new_contents: // @flow
  
  /**
   * CSS to style the placeholder psuedo-element.
   *
   * @example
   * // Styles as object usage
   * const styles = {
   *   ...placeholder({'color': 'blue'})
   * }
   *
   * // styled-components usage
   * const div = styled.input`
   *    ${placeholder({'color': 'blue'})}
   * `
   *
   * // CSS as JS Output
   *
   * 'input': {
   *   '&:-moz-placeholder': {
   *     'color': 'blue',
   *   },
   *   '&:-ms-input-placeholder': {
   *     'color': 'blue',
   *   },
   *   '&::-moz-placeholder': {
   *     'color': 'blue',
   *   },
   *   '&::-webkit-input-placeholder': {
   *     'color': 'blue',
   *   },
   * },
   */
  
  function placeholder(styles: Object, parent?: string = '&'): Object {
    return {
      [`${parent}::-webkit-input-placeholder`]: {
        ...styles,
      },
      [`${parent}:-moz-placeholder`]: {
        ...styles,
      },
      [`${parent}::-moz-placeholder`]: {
        ...styles,
      },
      [`${parent}:-ms-input-placeholder`]: {
        ...styles,
      },
    }
  }
  
  export default placeholder
  
subject: Correct the documentation for the placeholder mixin (#247)