Reuse computed properties in Vuejs2

Question

I have a calculation of totals of certain values in a pagination. This calculation is in a computed Property inserted into a component. The problem that I have another similar component that needs to use the same computed Property. Following is part of the code below referring only to the calculation of totals (if you wish I can post the component in full):

// ... dentro de methods
  vlr (param) {
    let today = new Date()
    today.setHours(0, 0, 0, 0)
    let venc = new Date(param.ven)
    venc.setHours(0, 0, 0, 0)

    if (venc.getTime() >= today.getTime()) {
      return parseFloat(param.total)
    }

    return param * 0.02
  }
},
computed: {
  getTotal (param) {
    let total = {}
    if (param.length) {
      param.forEach(idx => {
        idx.vlr = this.vlr(idx)
        Object.keys(idx).forEach(key => {
          if (!total[key]) {
            total[key] = {
              counter: 0,
              sum: 0,
              values: [],
              uniqueCounter: 0
            }
          }

          total[key].counter += 1
          total[key].sum += idx[key]

          if (total[key].values.indexOf(idx[key]) === -1) {
            total[key].uniqueCounter += 1
            total[key].values.push(idx[key])
          }
        })
      })
    }

    return total
  }
}

My question is exactly this. How to efficiently reuse a computed Property?

I tried to use with mixins, but I have not been successful so far for this situation.

Note: The code was made with Eslint.