src/vs/workbench/contrib/terminal/browser/terminalConfigHelper.ts/TerminalConfigHelper/_createCharMeasureElementIfNecessary
class TerminalConfigHelper:	private _createCharMeasureElementIfNecessary(): HTMLElement {
		if (!this.panelContainer) {
			throw new Error('Cannot measure element when terminal is not attached');
		}
		// Create charMeasureElement if it hasn't been created or if it was orphaned by its parent
		if (!this._charMeasureElement || !this._charMeasureElement.parentElement) {
			this._charMeasureElement = document.createElement('div');
			this.panelContainer.appendChild(this._charMeasureElement);
		}
		return this._charMeasureElement;
	}