src/vs/editor/common/viewModel/viewModelImpl.ts/ViewModel/tokenizeViewport
class ViewModel:	public tokenizeViewport(): void {
		const linesViewportData = this.viewLayout.getLinesViewportData();
		const viewVisibleRange = new Range(
			linesViewportData.startLineNumber,
			this.getLineMinColumn(linesViewportData.startLineNumber),
			linesViewportData.endLineNumber,
			this.getLineMaxColumn(linesViewportData.endLineNumber)
		);
		const modelVisibleRanges = this._toModelVisibleRanges(viewVisibleRange);

		for (const modelVisibleRange of modelVisibleRanges) {
			this.model.tokenization.tokenizeViewport(modelVisibleRange.startLineNumber, modelVisibleRange.endLineNumber);
		}
	}