package eu.javaexperience.collection; import java.util.Collection; import eu.javaexperience.interfaces.simple.getBy.GetBy1; public class CollectionFunctions { private CollectionFunctions(){} public static <T> GetBy1<Boolean, T> isIn(final Collection<T> coll) { return new GetBy1<Boolean, T>() { @Override public Boolean getBy(T a) { return coll.contains(a); } }; } }