if (cl.isEnum() || cl == Enum.class) flags |= ObjectStreamConstants.SC_ENUM;
  private void setFlags(Class cl)  {    if ((java.io.Externalizable.class).isAssignableFrom(cl))      flags |= ObjectStreamConstants.SC_EXTERNALIZABLE;    else if ((java.io.Serializable.class).isAssignableFrom(cl))      // only set this bit if CL is NOT Externalizable      flags |= ObjectStreamConstants.SC_SERIALIZABLE;    if (writeObjectMethod != null)      flags |= ObjectStreamConstants.SC_WRITE_METHOD;  }