code: def dvsep(s1, s2):
      
      assert len(s1) is 6 and len(s2) is 6
      s1 = stypes.toDoubleVector(s1)
      s2 = stypes.toDoubleVector(s2)
      return libspice.dvsep_c(s1, s2)
docs: Calculate the time derivative of the separation angle between
      two input states, S1 and S2.
  
      http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/dvsep_c.html
  
      :param s1: State vector of the first body.
      :type s1: 6-Element Array of floats
      :param s2: State vector of the second body.
      :type s2: 6-Element Array of floats
      :return: The time derivative of the angular separation between S1 and S2.
      :rtype: float