title: unable to insert values to the classAttributeAssignment in impex
body: <pre><code>$classificationSystem=hpeClassification 
  $classificationCatalogVersion=catalogversion(catalog(id[default=$classificationSystem]),version[default='1.0'])[unique=true,default=$classificationSystem:1.0] 
  $classificationSystemVersion=systemVersion(catalog(id[default=$classificationSystem]),version[default='1.0'])[unique=true,default=$classificationSystem:1.0]
  $code=/facet/Category
  $class=classificationClass($code,$classificationCatalogVersion)[unique=true]
  $attribute=classificationAttribute(code,$classificationSystemVersion)[unique=true]
  $unit=unit(code,$classificationSystemVersion)
  
  INSERT_UPDATE ClassAttributeAssignment;$class;$attribute;multiValued[default=false];range[default=false];attributeType(code[default=string]);localized[default=true];$unit;attributeValues(code,$classificationSystemVersion);
  </code></pre>