<?xml version="1.0"?>
  <special name="Special" desc="Special_parameter" xml:id="specialParam-treeRootNode">

    <group xml:id="ConstantsAll" name = "Constants" desc = "Usable constants for scalar, vector of matrix cases.">
      <parameter name ="Scalar" xml:id="constant_scal"/>
      <parameter name ="Vector" xml:id="constant_vec"/>
      <parameter name ="Matrix" xml:id="constant_mat"/>
    </group>
    <group xml:id="TimeStampAll" name="TimeStamp" desc="Time parameters : Timestamp gives you the elapsed time in seconds since 01/01/1970 and Timestamp from gives the same since a time decided by the user." >
      <parameter name='Timestamp' xml:id="timestamp"/>
      <parameter name='Timestamp From' xml:id="timestampfrom"/>

    </group>
  </special>