          return expression_wrapper % sql, expression_params
  
  
  class F(Combinable):
      """
      An object capable of resolving references to existing query objects.
      """
      def __init__(self, name):
          """
 
</s>
class TemporalSubtraction(CombinedExpression):
    def __init__(self, lhs, rhs):
        super(TemporalSubtraction, self).__init__(lhs, self.SUB, rhs, output_field=fields.DurationField())

    def as_sql(self, compiler, connection):
        connection.ops.check_expression_support(self)
        lhs = compiler.compile(self.lhs, connection)
        rhs = compiler.compile(self.rhs, connection)
        return connection.ops.subtract_temporals(self.lhs.output_field.get_internal_type(), lhs, rhs)


          return expression_wrapper % sql, expression_params
  
  
class TemporalSubtraction(CombinedExpression):
    def __init__(self, lhs, rhs):
        super(TemporalSubtraction, self).__init__(lhs, self.SUB, rhs, output_field=fields.DurationField())

    def as_sql(self, compiler, connection):
        connection.ops.check_expression_support(self)
        lhs = compiler.compile(self.lhs, connection)
        rhs = compiler.compile(self.rhs, connection)
        return connection.ops.subtract_temporals(self.lhs.output_field.get_internal_type(), lhs, rhs)


  class F(Combinable):
      """
      An object capable of resolving references to existing query objects.
      """
      def __init__(self, name):
          """
keep keep add keep keep keep keep keep keep
 Fixed #24793 -- Unified temporal difference support.
django/db/models/expressions.py