static void checkProductNumber(int n){
  if (n > MAX_PRODUCT_PAGE_SIZE) {
    throw new UnsupportedOperationException("Product page size exceeds the authorized size (" + MAX_PRODUCT_PAGE_SIZE + ").");
  }
}

static void checkProductNumber ( int n ) { if ( n > MAX_PRODUCT_PAGE_SIZE ) { throw new UnsupportedOperationException ( "Product page size exceeds the authorized size (" + MAX_PRODUCT_PAGE_SIZE + ")." ) ; } }
checks if the passed number as a number of product is acceptable according to the current configuration
