Fraction property in the icarBreedFractionsType model

[AlexeyHardCode]

Is it wise to make the 'fraction' property mandatory, NOT NULL within the 'BreedFractions' type of fractions list? We have a suspicion that if a breed has been specified in the 'BreedFractions' list, the fraction value must be set. Otherwise, why would it be left null or empty?

 "fractions": [
    {
        "breed": {
            "id": "09",
            "scheme": "breedcode"
        },
        "fraction": 100
    },
    {
        "breed": {
            "id": "12",
            "scheme": "breedcode"
        },
        "fraction": NULL
    }   
]

Suggestion:

1. Create new FractionValue type "icarBreedFractionValueType".

   {      
       "type": "object",
       "required": [
                          "breed",
                          "fraction"
                         ]
       "properties": {
         "breed": {
           "$ref": "icarBreedIdentifierType.json"
         },
         "fraction": {
           "type": "number",
           "nullable": false,
           "format": "double",
           "description": "The proportion of the denominator that this breed comprises."
         }        
   }

2. Include a reference to the newly created type within the 'fractions' array of the 'icarBreedFractionsType'.

[cookeac]

We've discussed and think there is a case where fraction could be null (if breed was known but not fractions). Therefore decided not to make this change for the moment.

We encourage everyone to fill this in if available.