text: // convert styles object to css string
  
  module.exports = function(styles) {
    return styles.map((s) => {
      var rules = '';
      for(var sel in s) {
        if(s.hasOwnProperty(sel)) {
          var style = s[sel];
          var rule = sel + '{';
          for(var k in style) {
            if(style.hasOwnProperty(k) && style[k] !== null
              && typeof style[k] !== 'undefined') {
              rule += (k+':'+style[k]+';');
            }
          }
          rule += '}';
          rules += rule;
        }
      }
  
      return rules;
    }).join('');
  };
  