title: jBPM simple work item - ioSpecification is not complete error
body: <p>i am trying to do simple work item from here: <a href="http://docs.jboss.org/jbpm/v5.4/userguide/ch.domain-specific-processes.html#d0e7389" rel="nofollow"><a href="http://docs.jboss.org/jbpm/v5.4/userguide/ch.domain-specific-processes.html#d0e7389" rel="nofollow">http://docs.jboss.org/jbpm/v5.4/userguide/ch.domain-specific-processes.html#d0e7389</a></a><br/><br/>my code:</p>
  
  <p>.wid file</p>
  
  <pre><code>import org.drools.process.core.datatype.impl.type.StringDataType;
  [
    // the Notification work item
    [
      "name" : "Notification",
      "parameters" : [
        "Message" : new StringDataType(),
        "From" : new StringDataType(),
        "To" : new StringDataType(),
        "Priority" : new StringDataType(),
      ],
      "displayName" : "Notification",
      "icon" : "icons/notification.gif"
    ]
  ]
  </code></pre>
  
  <p>then i implemented and registered work item handler with simple</p>
  
  <pre><code>@Override
  public void executeWorkItem(WorkItem workItem, WorkItemManager manager) {
      String from = (String) workItem.getParameter("From");
      System.out.println("from " + from);
  }
  </code></pre>
  
  <p>my custom node automatically appeared in eclipse modeler, so i made simple process:<br/> start > node > end<br/>and set value of 'From' parameter, but when executing it i get:</p>
  
  <pre><code>ERROR ExtensibleXmlParser:666 - (null: 24, 31): cvc-complex-type.2.4.b: The content of element 'bpmn2:ioSpecification' is not complete. One of '{"http://www.omg.org/spec/BPMN/20100524/MODEL":inputSet, "http://www.omg.org/spec/BPMN/20100524/MODEL":outputSet}' is expected.
  </code></pre>
  
  <p><strong>also 'from null' is printed</strong></p>
  
  <p>my bpmn file contains only one ioSpecification, and it have inputSet node</p>
  
  <pre><code>  &lt;bpmn2:ioSpecification id="_InputOutputSpecification_12"&gt;
      &lt;bpmn2:dataInput id="_DataInput_15" name="Message"/&gt;
      &lt;bpmn2:dataInput id="_DataInput_16" itemSubjectRef="ItemDefinition_4" name="From"/&gt;
      &lt;bpmn2:dataInput id="_DataInput_17" name="To"/&gt;
      &lt;bpmn2:dataInput id="_DataInput_18" name="Priority"/&gt;
      &lt;bpmn2:inputSet id="_InputSet_12" name="Input Set 12"&gt;
        &lt;bpmn2:dataInputRefs&gt;_DataInput_15&lt;/bpmn2:dataInputRefs&gt;
        &lt;bpmn2:dataInputRefs&gt;_DataInput_16&lt;/bpmn2:dataInputRefs&gt;
        &lt;bpmn2:dataInputRefs&gt;_DataInput_17&lt;/bpmn2:dataInputRefs&gt;
        &lt;bpmn2:dataInputRefs&gt;_DataInput_18&lt;/bpmn2:dataInputRefs&gt;
      &lt;/bpmn2:inputSet&gt;
    &lt;/bpmn2:ioSpecification&gt;
  </code></pre>
  
  <p>i am using jbpm 5.4.final<br/>
  eclipse BPMN2 Editor 0.2.5.201305082126<br/>
  eclipse JBoss jBPM5 Runtime Extension Feature   0.2.5.201305082126<br/>
  eclipse  JBoss jBPM Core    5.5.0.Final<br/>
  eclipse  JBoss jBPM Task    5.5.0.Final</p>