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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def dvhat(s1):
 """ Find the unit vector corresponding to a state vector and the derivative of the unit vector. http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/dvhat_c.html :param s1: State to be normalized. :type s1: 6-Element Array of floats :return: Unit vector s1 / abs(s1), and its time derivative. :rtype: 6-Element Array of floats """

    assert len(s1) is 6
    s1 = stypes.toDoubleVector(s1)
    sout = stypes.emptyDoubleVector(6)
    libspice.dvhat_c(s1, sout)
    return stypes.cVectorToPython(sout)