code: @Nullable
    private static String getPropertyDeprecationInfo(ObjectType type, String prop) {
      String depReason = getDeprecationReason(type.getOwnPropertyJSDocInfo(prop));
      if (depReason != null) {
        return depReason;
      }
  
      ObjectType implicitProto = type.getImplicitPrototype();
      if (implicitProto != null) {
        return getPropertyDeprecationInfo(implicitProto, prop);
      }
      return null;
    }
docs: Returns the deprecation reason for the property if it is marked
  as being deprecated. Returns empty string if the property is deprecated
  but no reason was given. Returns null if the property is not deprecated.