Add support for Entity/Relationship diagram

[Riduidel]

Currently, pyyed can generate UML diagrams by supporting a set of customizations in generated node object.

How is it possible to generate an entity-relationship diagram where entities are defined by the following XML fragment ?

    <node id="n0">
      <data key="d5"/>
      <data key="d6">
        <y:GenericNode configuration="com.yworks.entityRelationship.big_entity">
          <y:Geometry height="90.0" width="80.0" x="715.0" y="321.0"/>
          <y:Fill color="#E8EEF7" color2="#B7C9E3" transparent="false"/>
          <y:BorderStyle color="#000000" type="line" width="1.0"/>
          <y:NodeLabel alignment="center" autoSizePolicy="content" backgroundColor="#B7C9E3" configuration="com.yworks.entityRelationship.label.name" fontFamily="Dialog" fontSize="12" fontStyle="plain" hasLineColor="false" height="18.701171875" horizontalTextPosition="center" iconTextGap="4" modelName="internal" modelPosition="t" textColor="#000000" verticalTextPosition="bottom" visible="true" width="34.01171875" x="22.994140625" y="4.0">Entity</y:NodeLabel>
          <y:NodeLabel alignment="left" autoSizePolicy="content" configuration="com.yworks.entityRelationship.label.attributes" fontFamily="Dialog" fontSize="12" fontStyle="plain" hasBackgroundColor="false" hasLineColor="false" height="48.103515625" horizontalTextPosition="center" iconTextGap="4" modelName="custom" textColor="#000000" verticalTextPosition="top" visible="true" width="57.3671875" x="2.0" y="30.701171875">attribute 1
attribute 2
attribute 3<y:LabelModel>
              <y:ErdAttributesNodeLabelModel/>
            </y:LabelModel>
            <y:ModelParameter>
              <y:ErdAttributesNodeLabelModelParameter/>
            </y:ModelParameter>
          </y:NodeLabel>
          <y:StyleProperties>
            <y:Property class="java.lang.Boolean" name="y.view.ShadowNodePainter.SHADOW_PAINTING" value="true"/>
          </y:StyleProperties>
        </y:GenericNode>
      </data>
    </node>

As far as I understand pyyed code, I should set the node_type to GenericType (this I can do) and configuration to com.yworks.entityRelationship.big_entity. But how to do that? (I think there is also someting to do for entity name ...