src/vs/editor/common/viewModel/viewModelLines.ts/ViewModelLinesFromProjectedModel/modelPositionIsVisible
class ViewModelLinesFromProjectedModel:	public modelPositionIsVisible(modelLineNumber: number, _modelColumn: number): boolean {
		if (modelLineNumber < 1 || modelLineNumber > this.modelLineProjections.length) {
			// invalid arguments
			return false;
		}
		return this.modelLineProjections[modelLineNumber - 1].isVisible();
	}