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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 getid(self, ref):
 """Obtain the reference number of the vgroup following the vgroup with the given reference number . Args:: ref reference number of the vgroup after which to search; set to -1 to start the search at the start of the HDF file Returns:: reference number of the vgroup past the one identified by 'ref' An exception is raised if the end of the vgroup is reached. C library equivalent : Vgetid """


        num = _C.Vgetid(self._hdf_inst._id, ref)
        _checkErr('getid', num, "bad arguments or last vgroup reached")
        return num