code: public static String resolveClientId(FacesContext context, UIComponent source, String expression) {
          return resolveClientId(context, source, expression, SearchExpressionHint.NONE);
      }
docs: Resolves a {@link UIComponent} clientId and/or passtrough expression for the given expression.
  
  @param context The {@link FacesContext}.
  @param source The source component. E.g. a button.
  @param expression The search expression.
  @return A resolved clientId and/or passtrough expression (like PFS, widgetVar).