Time with offset constraint does not appear to be working correctly

[Tom-hayden]

Bug Report

When using an offset constraint with a non zero offset, datahelix incorrecly marks the profile as contradictory.

Steps to Reproduce:

run the profile

{
  "fields": [
    {
      "name": "time",
      "type": "time",
      "nullable": false
    },
    {
      "name": "anHourLater",
      "type": "time",
      "nullable": false
    }
  ],
      "constraints": [

        {
          "field": "anHourLater",
          "equalToField": "time",
          "offset": 1,
          "offsetUnit": "seconds"
        }
  ]
}

Expected Result:

times seperated by a second are produced.

Actual Result:

Generation started at: 10:55:19

Number of rows | Velocity (rows/sec) | Velocity trend
---------------+---------------------+---------------
* The provided profile is wholly contradictory!

[Ro4052]

Looks like there's some inversion happening, maybe here?

// FieldSpecGroupValueGenerator (createModifierForField lines 120-122)
if (!relation.main().equals(first)){
    relation = relation.inverse();
}

We end up with the offset being -1 so when the LinearRestrictions object is constructed, inclusiveMin is greater than inclusiveMax and the restriction is marked as contradictory.