@Override
    public boolean equals(final Object obj) {
        if (this == obj) {
            return true;
        }

        if (!(obj instanceof KeyValue)) {
            return false;
        }

        final KeyValue<?, ?> other = (KeyValue<?, ?>) obj;
        return Objects.equals(key, other.key) && Objects.equals(value, other.value);
    }
Create a new key-value pair.

@param key   the key
@param value the value
@param <K>   the type of the key
@param <V>   the type of the value
@return a new key-value pair
streams/src/main/java/org/apache/kafka/streams/KeyValue.java