polymer/test/unit/configure-elements.html

<script>
  var configureMixin = {

    published: {
      content: {
        type: String,
        notify: true
      }
    },
    
    bind: {
      content: 'contentChanged'
    },

    changeHandlerCount: 0,
        
    contentChanged: function() {
      this.changeHandlerReadyState = this._readied;
      this.changeHandlerCount++;
    }
  };

</script>

<template>
  <span id="content">{{content}}</span>
</template>
<script>
  Polymer({

    is: 'x-configure',

    mixins: [configureMixin],
    
    configure: function() {
      return {
        content: 'content'
      };
    }

  });
</script>


<template>
  <span id="content">{{content}}</span>
</template>
<script>
  Polymer({

    is: 'x-configure-gchild',

    mixins: [configureMixin],
    
    configure: function() {
      return {
        content: 'gchild'
      };
    }
    
  });
</script>

<template>
  <x-configure-gchild id="gchild" content="{{content}}"></x-configure-gchild>
</template>
<script>
  Polymer({

    is: 'x-configure-child',

    mixins: [configureMixin],
    
    configure: function() {
      return {
        content: 'child'
      };
    }
    
  });
</script>

<template>
  <x-configure-child id="child" content="{{content}}"></x-configure-child>
</template>
<script>
  Polymer({

    is: 'x-configure-host',

    mixins: [configureMixin],
    
    configure: function() {
      return {
        content: 'host'
      };
    }
    
  });
</script>