@Override
    public boolean equals(final Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        final ValueAndTimestamp<?> that = (ValueAndTimestamp<?>) o;
        return timestamp == that.timestamp &&
            Objects.equals(value, that.value);
    }
Return the wrapped {@code value} of the given {@code valueAndTimestamp} parameter
if the parameter is not {@code null}.

@param valueAndTimestamp a {@link ValueAndTimestamp} instance; can be {@code null}
@param <V> the type of the value
@return the wrapped {@code value} of {@code valueAndTimestamp} if not {@code null}; otherwise {@code null}
streams/src/main/java/org/apache/kafka/streams/state/ValueAndTimestamp.java