<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def dvdot(s1, s2):
 """ Compute the derivative of the dot product of two double precision position vectors. http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/dvdot_c.html :param s1: First state vector in the dot product. :type s1: 6-Element Array of floats :param s2: Second state vector in the dot product. :type s2: 6-Element Array of floats :return: The derivative of the dot product. :rtype: float """

    assert len(s1) is 6 and len(s2) is 6
    s1 = stypes.toDoubleVector(s1)
    s2 = stypes.toDoubleVector(s2)
    return libspice.dvdot_c(s1, s2)