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);
  
          BorderLeftWidth borderLeftWidth = null;
          BorderLeftStyle borderLeftStyle = null;
          BorderLeftColor borderLeftColor = null;
  
          for (final String eachPart : cssValueParts) {
  
              boolean invalid = true;
              if (borderLeftWidth == null && BorderLeftWidth.isValid(eachPart)) {
                  borderLeftWidth = new BorderLeftWidth(eachPart);
                  invalid = false;
              } else if (borderLeftStyle == null
                      && BorderLeftStyle.isValid(eachPart)) {
                  borderLeftStyle = BorderLeftStyle.getThis(eachPart);
                  invalid = false;
              } else if (borderLeftColor == null
                      && BorderLeftColor.isValid(eachPart)) {
                  borderLeftColor = new BorderLeftColor(eachPart);
                  invalid = false;
              }
              if (invalid) {
                  return false;
              }
          }
  
          return borderLeftWidth != null || borderLeftStyle != null
                  || borderLeftColor != 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