for q in qs

        if not q.equals

          throw new Error("doesn't look like a proper Quad")

        if not q.graph?

          throw new Error("corrupt patch: #{JSON.stringify(q)}")

  _applyPatch: (patch) ->

    # In most cases you want applyAndSendPatch.

    # 

    # This is the only method that writes to @graph!

    @cachedFloatValues.clear()

    for quad in patch.delQuads

      did = @graph.removeQuad(quad)

    for quad in patch.addQuads

      @graph.addQuad(quad)

    #log('applied patch locally', patchSizeSummary(patch))

    @_autoDeps.graphChanged(patch)

  getObjectPatch: (s, p, newObject, g) ->

    # make a patch which removes existing values for (s,p,*,c) and

    # adds (s,p,newObject,c). Values in other graphs are not affected.

    existing = @graph.getQuads(s, p, null, g)

    return {

      delQuads: existing,

      addQuads: [@Quad(s, p, newObject, g)]

    # helps with memleak? not sure yet. The point was if two matching

    # labels get puushed on, we should run only one. So maybe

    # appending a serial number is backwards.

    @serial = 1 if not @serial

    @serial += 1

    #label = label + @serial

    @_autoDeps.runHandler(func, label)

  _singleValue: (s, p) ->

    @_autoDeps.askedFor(s, p, null, null)

    quads = @graph.getQuads(s, p)

    objs = new Set(q.object for q in quads)

    switch objs.size

      when 0

        throw new Error("no value for "+s.value+" "+p.value)

      when 1

        obj = objs.values().next().value

        return obj

      else

        throw new Error("too many different values: " + JSON.stringify(quads))

  floatValue: (s, p) ->

<link rel="import" href="/lib/polymer/polymer-element.html">

<script src="/node_modules/n3/n3-browser.js"></script>

<script src="/lib/async/dist/async.js"></script>

      <script src="/lib/underscore/underscore-min.js"></script>

<dom-module id="rdfdb-synced-graph">

  <template>

    <style>

     :host {

         display: inline-block;

         border: 1px solid gray;

         background: #05335a;

         color: #4fc1d4;

     }

    </style>

    graph: [[status]]

  </template>

  <script src="rdfdbclient.js"></script>

  <script src="graph.js"></script>

  <script>

   class RdfdbSyncedGraph extends Polymer.Element {

       static get is() { return "rdfdb-synced-graph"; }