code: function objToRule(obj, clonedRule) {
    var rule = clonedRule || postcss.rule();
    var skipKeys = ['selector', 'selectors', 'source'];
  
    if (obj.selector)
      rule.selector = obj.selector;
    else if (obj.selectors)
      rule.selectors = obj.selectors;
  
    if (obj.source)
      rule.source = obj.source;
  
    for (var k in obj) {
      if (obj.hasOwnProperty(k) && !(skipKeys.indexOf(k) + 1)) {
        var v = obj[k];
        var found = false;
  
        // If clonedRule was passed in, check for an existing property.
        if (clonedRule) {
          rule.each(function(decl) {
            if (decl.prop == k) {
              decl.value = v;
              found = true;
              return false;
            }
          });
        }
  
        // If no clonedRule or there was no existing prop.
        if (!clonedRule || !found)
          rule.append({ prop: k, value: v });
      }
    }
  
    return rule;
  }
docs: Convert a js obj to a postcss rule, extending clonedRule if it is passed in.