def _next(self):
        """
            Get next variable ID. Skip occupied intervals if any.
        """

        self.top += 1

        while self._occupied and self.top >= self._occupied[0][0]:
            if self.top <= self._occupied[0][1]:
                self.top = self._occupied[0][1] + 1

            self._occupied.pop(0)

        return self.top
def _next ( self ) : self . top += 1 while self . _occupied and self . top >= self . _occupied [ 0 ] [ 0 ] : if self . top <= self . _occupied [ 0 ] [ 1 ] : self . top = self . _occupied [ 0 ] [ 1 ] + 1 self . _occupied . pop ( 0 ) return self . top
Get next variable ID. Skip occupied intervals if any.