How to use the ngx-custom-validators.CustomValidators.gt function in ngx-custom-validators

dateISO: {
      func: CustomValidators.dateISO
    },
    digits: {
      func: CustomValidators.digits
    },
    equal: {
      func: CustomValidators.equal,
      params: ["equal"]
    },
    equalTo: {
      func: CustomValidators.equalTo,
      params: ["equalTo"]
    },
    gt: {
      func: CustomValidators.gt,
      params: ["gt"]
    },
    gte: {
      func: CustomValidators.gte,
      params: ["gte"]
    },
    json: {
      func: CustomValidators.json
    },
    lt: {
      func: CustomValidators.lt,
      params: ["lt"]
    },
    lte: {
      func: CustomValidators.lte,
      params: ["lte"]