parseArrayData(meta, data, start, count) {
    const {xScale, yScale} = meta;
    const parsed = new Array(count);
    let i, ilen, index, item;

    for (i = 0, ilen = count; i < ilen; ++i) {
      index = i + start;
      item = data[index];
      parsed[i] = {
        x: xScale.parse(item[0], index),
        y: yScale.parse(item[1], index)
      };
    }
    return parsed;
  }
Parse array of arrays
@param {object} meta - dataset meta
@param {array} data - data array. Example [[1,2],[3,4]]
@param {number} start - start index
@param {number} count - number of items to parse
@returns {object} parsed item - item containing index and a parsed value
for each scale id.
Example: {x: 0, y: 1}
@protected