@Override
    public R getValue() {
        return getRight();
    }
Creates a {@link Stream} of zero or one Pairs if the mapping function
returns a non-empty {@link Optional}.

@param left Value to set as the left side of the pair.
@param f Mapping function that accepts the left value and returns an
 Optional value.
@param <L> Left value type.
@param <R> Right value type.
@return Returns a Stream that contains either a single Pair if the
 Optional is not empty, or an empty Stream.
smithy-utils/src/main/java/software/amazon/smithy/utils/Pair.java