/**
     * Enable or disable result collapsing for similar documents.
     * When enabled, similar search results are grouped together.
     */
    @Size(max = 10)
    public String resultCollapsed;

    /**
     * Enable or disable display of login link in the search interface.
     * When enabled, a login link is shown to unauthenticated users.
     */
    @Size(max = 10)