getPreviousPath(realIndex, j) {
    let w = this.w
    let pathFrom = 'M 0 0'
    for (let pp = 0; pp < w.globals.previousPaths.length; pp++) {
      let gpp = w.globals.previousPaths[pp]

      if (
        gpp.paths &&
        gpp.paths.length > 0 &&
        parseInt(gpp.realIndex, 10) === parseInt(realIndex, 10)
      ) {
        if (typeof w.globals.previousPaths[pp].paths[j] !== 'undefined') {
          pathFrom = w.globals.previousPaths[pp].paths[j].d
        }
      }
    }
    return pathFrom
  }
getPreviousPath is a common function for bars/columns which is used to get previous paths when data changes.
@memberof Bar
@param {int} realIndex - current iterating i
@param {int} j - current iterating series's j index
@return {string} pathFrom is the string which will be appended in animations