@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		PongMessage other = (PongMessage) obj;
		if (correlationId == null) {
			if (other.correlationId != null)
				return false;
		} else if (!correlationId.equals(other.correlationId))
			return false;
		if (_id == null) {
			if (other._id != null)
				return false;
		} else if (!_id.equals(other._id))
			return false;
		return true;
	}