r0 := UnboundTable: t
  col int64

Aggregate[r0]
  metrics:
    sum:  StructField(ReductionVectorizedUDF(func=multi_output_udf, func_args=[r0.col], input_type=[int64], return_type={'sum': int64, 'mean': float64}), field='sum')
    mean: StructField(ReductionVectorizedUDF(func=multi_output_udf, func_args=[r0.col], input_type=[int64], return_type={'sum': int64, 'mean': float64}), field='mean')