RoboconfError { @Override public int hashCode() { return this.errorCode == null ? 47 : this.errorCode.hashCode(); } RoboconfError( ErrorCode errorCode );  RoboconfError( ErrorCode errorCode, ErrorDetails... details ); ErrorCode getErrorCode(); void setErrorCode( ErrorCode errorCode ); ErrorDetails[] getDetails(); void setDetails( ErrorDetails... details ); @Override String toString(); @Override boolean equals( Object obj ); @Override int hashCode();  }
@Test public void testHashCode() { Assert.assertTrue( new RoboconfError( null ).hashCode() > 0 ); Assert.assertTrue( new RoboconfError( ErrorCode.CMD_CANNOT_HAVE_ANY_PARENT ).hashCode() > 0 ); }