code: function space(rules, i) {
    var rule = rules[i]
      , j = i - 1
      , peek = rules[j]
      , result = ''
      , ruleRoot
      , peekRoot
      , ruleVal
      , peekVal
  
    // skip if not peak, rule, or rule.name
    if (!peek || !rule || !rule.name) return
  
    // if previous rule is not a css property, try searching up tree for nearest rule
    while (!peek.name) {
      peek = rules[j--]
  
      // if none, then exit
      if (!peek) return
    }
  
    // check to see if name has a vnedor prefix
    if (VENDOR_PREFIX.test(peek.name)) {
  
      // strip vendor prefix from rule and prior rule
      ruleRoot = rule.name.replace(VENDOR_PREFIX, '')
      peekRoot = peek.name.replace(VENDOR_PREFIX, '')
  
  
      // if they share the same root calculate the offset in spacing
      if (ruleRoot === peekRoot) {
  
        // calculate the rules val
        ruleVal = rule.name.match(VENDOR_PREFIX)
        ruleVal = (ruleVal && ruleVal[0].length) || 0
  
        // calculate the peeks val
        peekVal = peek.name.match(VENDOR_PREFIX)
        peekVal = (peekVal && peekVal[0].length) || 0
  
        // if peek has a value, offset the rule val
        if (peekVal) {
          ruleVal = peekVal - ruleVal
          while (ruleVal--) result += ' '
        }
  
      }
    }
  
    // prefix the rule with the white space offset
    rule.name = result + rule.name
  }
docs: space defintion