function makeMap(sourceBatch, map, otherMap) {
	            for (var i = 0, len = sourceBatch.length; i < len; i++) {
	                var seriesId = sourceBatch[i].seriesId;
	                var dataIndices = modelUtil.normalizeToArray(sourceBatch[i].dataIndex);
	                var otherDataIndices = otherMap && otherMap[seriesId];

	                for (var j = 0, lenj = dataIndices.length; j < lenj; j++) {
	                    var dataIndex = dataIndices[j];

	                    if (otherDataIndices && otherDataIndices[dataIndex]) {
	                        otherDataIndices[dataIndex] = null;
	                    }
	                    else {
	                        (map[seriesId] || (map[seriesId] = {}))[dataIndex] = 1;
	                    }
	                }
	            }
	        }
A helper for removing duplicate items between batchA and batchB,
and in themselves, and categorize by series.

@param {Array.<Object>} batchA Like: [{seriesId: 2, dataIndex: [32, 4, 5]}, ...]
@param {Array.<Object>} batchB Like: [{seriesId: 2, dataIndex: [32, 4, 5]}, ...]
@return {Array.<Array.<Object>, Array.<Object>>} result: [resultBatchA, resultBatchB]