code: def solve_minmax(self, expr):
          
          if isinstance(expr, int):
              return expr
          expr = self.migrate_expression(expr)
          return self._solver.minmax(self._constraints, expr)
docs: Solves a symbolic :class:`~manticore.core.smtlib.expression.Expression` into
          its minimum and maximun solution. Only defined for bitvects.
  
          :param manticore.core.smtlib.Expression expr: Symbolic value to solve
          :return: Concrete value
          :rtype: list[int]