wffweb/src/main/java/com/webfirmframework/wffweb/css/css3/BackgroundSize.java
public static boolean isValid(final String cssValue) {
        final String trimmedCssValue = TagStringUtil
                .toLowerCase(StringUtil.strip(cssValue));

        final String[] cssValueParts = StringUtil.splitBySpace(trimmedCssValue);
        if (cssValueParts.length > 2) {
            return false;
        }
        if (PREDEFINED_CONSTANTS.contains(trimmedCssValue)) {
            return true;
        }

        boolean valid = false;
        for (final String each : cssValueParts) {
            final Object[] lengthValueAndUnit = CssLengthUtil
                    .getLengthValueAsPremitiveAndUnit(each);
            if (lengthValueAndUnit.length != 2) {
                return false;
            }
            valid = true;
        }
        return valid;
    }
public static boolean isValid(final String cssValue) {
        final String trimmedCssValue = TagStringUtil
                .toLowerCase(StringUtil.strip(cssValue));

        final String[] cssValueParts = StringUtil.splitBySpace(trimmedCssValue);
        if (cssValueParts.length > 2) {
            return false;
        }
        if (PREDEFINED_CONSTANTS.contains(trimmedCssValue)) {
            return true;
        }

        boolean valid = false;
        for (final String each : cssValueParts) {
            final Object[] lengthValueAndUnit = CssLengthUtil
                    .getLengthValueAsPremitiveAndUnit(each);
            if (lengthValueAndUnit.length != 2) {
                return false;
            }
            valid = true;
        }
        return valid;
    }
validates if the given cssValue is valid for this class.

@param cssValue
the value to check.
@return true if valid and false if invalid.
@author WFF
@since 1.0.0