Connection 012

The pipeline

<p:declare-step xmlns:err="http://www.w3.org/ns/xproc-error" xmlns:p="http://www.w3.org/ns/xproc" xmlns:test="http://test" version="3.0">
   <p:output port="result"/>
   <p:declare-step type="test:step">
      <p:output port="result" sequence="true"/>
      <p:input port="source">
         <p:empty/>
      </p:input>
      <p:identity/>
   </p:declare-step>
   <test:step/>
   <p:wrap-sequence wrapper="result"/>
</p:declare-step>