docs: def visitExponentExpression(self, ctx):
          """
          expression: expression EXPONENT expression
          """
          arg1 = conversions.to_decimal(self.visit(ctx.expression(0)), self._eval_context)
          arg2 = conversions.to_decimal(self.visit(ctx.expression(1)), self._eval_context)
          return conversions.to_decimal(decimal_pow(arg1, arg2), ctx)