{
    "number1": { "number_between": [10,20] },
    "number2": [ { "number_between": [10,20] } ],
    "number3": [ { "number_between": [-10,10] } ],
    "number4": [ { "number_between": [-10,10] } ],
    "empty_field": { "number_between": [10,20] },

    "value_is_string":      { "number_between": [10,20] },
    "value_is_hash":        { "number_between": [10,20] },
    "value_is_empty_hash":  { "number_between": [10,20] },
    "value_is_array":       { "number_between": [10,20] },
    "value_is_empty_array": { "number_between": [10,20] }
}