src/vs/editor/common/model/prefixSumComputer.ts/PrefixSumComputer/insertValues
class PrefixSumComputer:	public insertValues(insertIndex: number, insertValues: Uint32Array): boolean {
		insertIndex = toUint32(insertIndex);
		const oldValues = this.values;
		const oldPrefixSum = this.prefixSum;
		const insertValuesLen = insertValues.length;

		if (insertValuesLen === 0) {
			return false;
		}

		this.values = new Uint32Array(oldValues.length + insertValuesLen);
		this.values.set(oldValues.subarray(0, insertIndex), 0);
		this.values.set(oldValues.subarray(insertIndex), insertIndex + insertValuesLen);
		this.values.set(insertValues, insertIndex);

		if (insertIndex - 1 < this.prefixSumValidIndex[0]) {
			this.prefixSumValidIndex[0] = insertIndex - 1;
		}

		this.prefixSum = new Uint32Array(this.values.length);
		if (this.prefixSumValidIndex[0] >= 0) {
			this.prefixSum.set(oldPrefixSum.subarray(0, this.prefixSumValidIndex[0] + 1));
		}
		return true;
	}