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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 use(wcspkg, raise_err=True):
 """Choose WCS package."""

    global coord_types, wcs_configured, WCS

    if wcspkg not in common.custom_wcs:
        # Try to dynamically load WCS
        modname = 'wcs_%s' % (wcspkg)
        path = os.path.join(wcs_home, '%s.py' % (modname))
        try:
            my_import(modname, path)
        except ImportError:
            return False

    if wcspkg in common.custom_wcs:
        bnch = common.custom_wcs[wcspkg]
        WCS = bnch.wrapper_class
        coord_types = bnch.coord_types
        wcs_configured = True
        return True

    return False