Class Coerce is a {@link SubAssembly} that will coerce all incoming {@link cascading.tuple.Tuple} values tothe given types.
If the given type is a primitive ( {@code long}), and the tuple value is null, {@code 0} is returned.If the type is an Object ( {@code java.lang.Long}), and the tuple value is {@code null}, {@code null} is returned.
Coerce encapsulates the {@link Identity} function.
@see cascading.pipe.SubAssembly
@see cascading.operation.Identity