Circular component hierarchies aren't picked up

[MichaelClerx]

<?xml version="1.0" encoding="UTF-8"?>
<!-- CellML Test Suite. https://github.com/MichaelClerx/cellml-validation -->
<!-- CellML 1.0, 6.4.3.2: A hierarchy cannot be circular -->
<model name="component_ref_cycle_5"
       xmlns="http://www.cellml.org/cellml/1.0#">
  <component name="A" />
  <group>
    <relationship_ref relationship="encapsulation" />
    <component_ref component="A" >
      <component_ref component="A" />
    </component_ref>
  </group>
</model>

<?xml version="1.0" encoding="UTF-8"?>
<!-- CellML Test Suite. https://github.com/MichaelClerx/cellml-validation -->
<!-- CellML 1.0, 6.4.3.2: A hierarchy cannot be circular -->
<model name="component_ref_cycle_7"
       xmlns="http://www.cellml.org/cellml/1.0#">
  <component name="A" />
  <component name="B" />
  <component name="C" />
  <group>
    <relationship_ref relationship="encapsulation" />
    <component_ref component="A" >
      <component_ref component="B" />
    </component_ref>
    <component_ref component="B">
      <component_ref component="C">
        <component_ref component="A" />
      </component_ref>
    </component_ref>
  </group>
</model>