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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 sizeof(self, fields):
 """Retrieve the size in bytes of the given fields. Args:: fields sequence of field names to query Returns:: total size of the fields in bytes C library equivalent : VSsizeof """


        if type(fields) in [tuple, list]:
            str = ','.join(fields)
        else:
            str = fields
        n = _C.VSsizeof(self._id, str)
        _checkErr('sizeof', n, "cannot retrieve field sizes")
        return n