src/vs/editor/contrib/gotoSymbol/link/clickLinkGesture.ts/ClickLinkGesture/_onEditorMouseDown
class ClickLinkGesture:	private _onEditorMouseDown(mouseEvent: ClickLinkMouseEvent): void {
		// We need to record if we had the trigger key on mouse down because someone might select something in the editor
		// holding the mouse down and then while mouse is down start to press Ctrl/Cmd to start a copy operation and then
		// release the mouse button without wanting to do the navigation.
		// With this flag we prevent goto definition if the mouse was down before the trigger key was pressed.
		this._hasTriggerKeyOnMouseDown = mouseEvent.hasTriggerModifier;
		this._lineNumberOnMouseDown = mouseEvent.target.position ? mouseEvent.target.position.lineNumber : 0;
	}