function Category(splitList) {
    this.splitList = splitList || {
        other: 1
    };
}
Choropleth
@param {Object} splitList:
      [
          {
              start: 0,
              end: 2,
              value: randomColor()
          },{
              start: 2,
              end: 4,
              value: randomColor()
          },{
              start: 4,
              value: randomColor()
          }
      ];