<?xml version="1.0" ?>
<sdf version="1.7">
  <world name="default">
    <model name="parent_model">
      <link name="L1"/>
      <link name="L2">
        <pose>0 1 0 0 0 0</pose>
      </link>
      <model name="M1">
        <pose>1 0 0 0 1.5707963267948966 0</pose>
        <link name="L">
          <pose>0 0 1 0 0 0</pose>
        </link>
      </model>
      <model name="M2">
        <pose relative_to="">2 0 0 0 0 0</pose>
        <link name="L">
          <pose>0 0 1 0 0 0</pose>
        </link>
      </model>
      <model name="M3">
        <pose relative_to="M1">3 0 0 0 0 0</pose>
        <link name="L">
          <pose>0 0 1 0 0 0</pose>
        </link>
      </model>

      <frame name="F1">
        <pose relative_to="M3">0 1 0 0 0 0</pose>
      </frame>

      <joint name="J1" type="revolute">
        <pose relative_to="F1">1 0 0 0 0 0</pose>
        <parent>L1</parent>
        <child>L2</child>
        <axis>
          <xyz>1 0 0</xyz>
        </axis>
      </joint>
    </model>
  </world>
</sdf>

