<?xml version="1.0" standalone="yes"?>

<wo class="WECase">
  <binding name="key" />
  <binding name="keys" />
  
  <validation message="either &apos;key&apos; or &apos;keys&apos; may be bound">
    <count test="!=1">
      <bound name="key" />
      <bound name="keys" />
    </count>
  </validation>
</wo>
