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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 _get_full_key(self, key):
 """Returns full key even if table is omitted"""


        length = len(key)

        if length == 3:
            return key

        elif length == 2:
            row, col = key
            tab = self.grid.current_table
            return row, col, tab

        else:
            msg = _("Key length {length}  not in (2, 3)").format(length=length)
            raise ValueError(msg)