code: function kill(i) {
      if(dead[i]) {
        return
      }
      //Kill vertex
      dead[i] = true
      //Fixup topology
      var s = inv[i]
      var t = outv[i]
      if(inv[t] >= 0) {
        inv[t] = s
      }
      if(outv[s] >= 0) {
        outv[s] = t
      }
  
      //Update weights on s and t
      if(index[s] >= 0) {
        heapUpdate(index[s], computeWeight(s))
      }
      if(index[t] >= 0) {
        heapUpdate(index[t], computeWeight(t))
      }
    }
docs: Kills a vertex (assume vertex already removed from heap)