code: public static boolean isValid(final String cssValue) {
          // TODO modify to make a strict validation
          if (cssValue == null || StringUtil.isBlank(cssValue)) {
              return false;
          }
  
          final String[] cssValueParts = StringUtil.splitBySpace(cssValue);
  
          MozFlexGrow mozFlexGrow = null;
          MozFlexShrink mozFlexShrink = null;
          MozFlexBasis mozFlexBasis = null;
  
          for (final String eachPart : cssValueParts) {
              boolean invalid = true;
  
              if (mozFlexGrow == null && MozFlexGrow.isValid(eachPart)) {
                  mozFlexGrow = new MozFlexGrow(eachPart);
                  invalid = false;
              } else if (mozFlexShrink == null
                      && MozFlexShrink.isValid(eachPart)) {
                  mozFlexShrink = new MozFlexShrink(eachPart);
                  invalid = false;
              } else if (mozFlexBasis == null && MozFlexBasis.isValid(eachPart)) {
                  mozFlexBasis = new MozFlexBasis(eachPart);
                  invalid = false;
              }
              if (invalid) {
                  return false;
              }
          }
  
          return mozFlexGrow != null || mozFlexShrink != null
                  || mozFlexBasis != 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