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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 ossos_pointings(self):
 """ plot an OSSOS observation on the OSSOS plot. """

        match = re.match('(\d+)\D(\d+)', self.expnum.get())
        if match is not None:
            expnum = int(match.group(1))
            ccd = int(match.group(2))
            x = 2112 / 2.0
            y = 4644 / 2.0
        else:
            expnum = int(str(self.expnum.get()))
            ccd = 22
            x = 1000
            y = 4644 - 15 / 0.185
        header = None
        try:
            header = storage.get_astheader(expnum, ccd=ccd)
        except:
            if header is None:
                print "Didn't get a header... "
                return

        ossos_wcs = wcs.WCS(header)
        (ra, dec) = ossos_wcs.xy2sky(x, y)

        class MyEvent(object):
            def __init__(self, x, y):
                self.x = x
                self.y = y

        (x, y) = self.p2s((math.radians(ra), math.radians(dec)))
        event = MyEvent(x, y)
        self.create_pointing(event, label_text=header['OBJECT'] + ' ccd{}'.format(ccd))