code: function injectStyle(obj) {
    if (!obj) return ''
  
    var selectors = Object.keys(obj)
  
    var styles = selectors.map(function(key) {
      var selector = obj[key]
      var style = inlineStyle(selector)
      var inline = key.concat('{').concat(style).concat('}')
      return inline
    })
  
    var results = styles.join('')
    insertCss(results)
  
    return results
  }
docs: Inject `obj` as an inline CSS string.
  
  @param {Object} obj
  @return {String}