code: public void setStyleProperty(Element e, String prop, String val) {
      if (e == null || prop == null) {
        return;
      }
      prop = fixPropertyName(prop);
      // put it in lower-case only when all letters are upper-case, to avoid
      // modifying already camelized properties
      if (prop.matches("^[A-Z]+$")) {
        prop = prop.toLowerCase();
      }
      prop = JsUtils.camelize(prop);
      if (val == null || val.trim().length() == 0) {
        removeStyleProperty(e, prop);
      } else {
        if (val.matches("-?[\\d\\.]+") && !cssNumberRegex.test(prop)) {
          val += "px";
        }
        e.getStyle().setProperty(prop, val);
      }
    }
docs: Set the value of a style property of an element.