<element name="cylinder" required="0">
  <description>Cylinder shape</description>
  <element name="radius" type="double" default="1" required="1">
    <description>Radius of the cylinder</description>
  </element>
  <element name="length" type="double" default="1" required="1">
    <description>Length of the cylinder</description>
  </element>
</element>
