docs: public static ExpectedCondition<Boolean> attributeContains(final WebElement element,
                                                               final String attribute,
                                                               final String value) {
      return new ExpectedCondition<Boolean>() {
        private String currentValue = null;
  
        @Override
        public Boolean apply(WebDriver driver) {
          return getAttributeOrCssValue(element, attribute)
              .map(seen -> seen.contains(value))
              .orElse(false);
        }
  
        @Override
        public String toString() {
          return String.format("value to contain \"%s\". Current value: \"%s\"", value, currentValue);
        }
      };
    }