code: protected String getStringValue(CmsObject cms, I_CmsXmlContentValueLocation location, String defaultValue) {
  
          if (location == null) {
              return defaultValue;
          }
          return location.asString(cms);
      }
docs: Converts a (possibly null) content value location to a string.<p>
  
  @param cms the current CMS context
  @param location the content value location
  @param defaultValue the value to return if the location is null
  
  @return the string value of the content value location