Should Datasource Plugins return datapoints in time order?

If query(options) returns datapoints in the format

[
  {
    "target":"sometarget",
    "datapoints":[
      [622, 1450754160000],
      [365, 1450754220000]
    ]
  }

Should datapoints be sorted by timestamp in ascending order? I haven’t been able to confirm this in the documentation or in the source code itself.