src/vs/platform/terminal/node/terminalProcess.ts/TerminalProcess/acknowledgeDataEvent
class TerminalProcess:	acknowledgeDataEvent(charCount: number): void {
		// Prevent lower than 0 to heal from errors
		this._unacknowledgedCharCount = Math.max(this._unacknowledgedCharCount - charCount, 0);
		this._logService.trace(`Flow control: Ack ${charCount} chars (unacknowledged: ${this._unacknowledgedCharCount})`);
		if (this._isPtyPaused && this._unacknowledgedCharCount < FlowControlConstants.LowWatermarkChars) {
			this._logService.trace(`Flow control: Resume (${this._unacknowledgedCharCount} < ${FlowControlConstants.LowWatermarkChars})`);
			this._ptyProcess?.resume();
			this._isPtyPaused = false;
		}
	}