code: public static void unregisterCSSIncludeFromThisRequest (@Nonnull final ICSSPathProvider aCSSPathProvider)
    {
      final CSSResourceSet aSet = _getPerRequestSet (false);
      if (aSet != null)
        aSet.removeItem (aCSSPathProvider);
    }
docs: Unregister an existing CSS item only from this request
  
  @param aCSSPathProvider
  The CSS path provider to use. May not be <code>null</code>.