src/vs/editor/contrib/parameterHints/parameterHintsModel.ts/ParameterHintsModel/previous
class ParameterHintsModel:	public previous(): void {
		if (this.state.type !== ParameterHintState.Type.Active) {
			return;
		}

		const length = this.state.hints.signatures.length;
		const activeSignature = this.state.hints.activeSignature;
		const first = activeSignature === 0;
		const cycle = this.editor.getOption(EditorOption.parameterHints).cycle;

		// If there is only one signature, or we're on first signature of list
		if ((length < 2 || first) && !cycle) {
			this.cancel();
			return;
		}

		this.updateActiveSignature(first && cycle ? length - 1 : activeSignature - 1);
	}