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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 vec2ang(vectors, lonlat=False):
 """Drop-in replacement for healpy `~healpy.pixelfunc.vec2ang`."""

    x, y, z = vectors.transpose()
    rep_car = CartesianRepresentation(x, y, z)
    rep_sph = rep_car.represent_as(UnitSphericalRepresentation)
    return _lonlat_to_healpy(rep_sph.lon.ravel(), rep_sph.lat.ravel(), lonlat=lonlat)