@Nonnull
    @Deprecated
    public static <T1, T2> Function<Pair<? extends T1, ? extends T2>, ? extends T1> fst(@Nonnull final Class<T1> clazz) {
        return new First<>();
    }
@ Nonnull @ Deprecated public static < T1 , T2 > Function < Pair < ? extends T1 , ? extends T2 > , ? extends T1 > fst ( @ Nonnull final Class < T1 > clazz ) { return new First < > ( ) ; }
Makes grabbing the first value out of a collection of Pairs a bit easier, e.g.
given an iterable over Pair.of(String, ?) objects:

<br>
<code>... = Iterables.transform(iterable, Pair.fst(String.class))</code>

@param clazz The class type for a.
@param <T1> Expected data type for {@link Pair#a}
@param <T2> Expected data type for {@link Pair#b}
@return a Function that returns null or the first value of the Pair, which also may be null
@deprecated use {@link #fst()}.