code: public static boolean isValid(final String cssValue) {
          // TODO modify to make a strict validation
          if (cssValue == null || StringUtil.isBlank(cssValue)) {
              return false;
          }
  
          final List<String> cssValueParts = CssValueUtil.split(cssValue);
  
          BorderTopWidth borderTopWidth = null;
          BorderTopStyle borderTopStyle = null;
          BorderTopColor borderTopColor = null;
  
          for (final String eachPart : cssValueParts) {
  
              boolean invalid = true;
              if (borderTopWidth == null && BorderTopWidth.isValid(eachPart)) {
                  borderTopWidth = new BorderTopWidth(eachPart);
                  invalid = false;
              } else if (borderTopStyle == null
                      && BorderTopStyle.isValid(eachPart)) {
                  borderTopStyle = BorderTopStyle.getThis(eachPart);
                  invalid = false;
              } else if (borderTopColor == null
                      && BorderTopColor.isValid(eachPart)) {
                  borderTopColor = new BorderTopColor(eachPart);
                  invalid = false;
              }
              if (invalid) {
                  return false;
              }
          }
  
          return borderTopWidth != null || borderTopStyle != null
                  || borderTopColor != null;
      }
docs: checks the given css value is valid for this class. It does't do a strict
  validation.
  
  @param cssValue
  @return
  @since 1.0.0
  @author WFF