src/vs/editor/common/tokens/sparseMultilineTokens.ts/SparseMultilineTokensStorage/getMaxDeltaLine
class SparseMultilineTokensStorage:	public getMaxDeltaLine(): number {
		const tokenCount = this._getTokenCount();
		if (tokenCount === 0) {
			return -1;
		}
		return this._getDeltaLine(tokenCount - 1);
	}