<?xml version="1.0" ?>
<sdf version='1.7'>
  <model name="model_frame_attached_to_joint">
    <link name="P"/>
    <link name="C"/>
    <joint name="J" type="fixed">
      <parent>P</parent>
      <child>C</child>
    </joint>
    <frame name="F1" attached_to="P"/>   <!-- VALID: Directly attached_to link P. -->
    <frame name="F2" attached_to="C"/>   <!-- VALID: Directly attached_to link C. -->
    <frame name="F3" attached_to="J"/>   <!-- VALID: Indirectly attached_to link C via joint J. -->
    <frame name="F4" attached_to="F3"/>  <!-- VALID: Indirectly attached_to link C via frame F3. -->
  </model>
</sdf>
