ImmutableSet.java

package io.github.hkusu.example.lib.type;

import android.support.annotation.NonNull;

import java.util.LinkedHashSet;
import java.util.Set;

public class ImmutableSet<T> {
    private final Set<T> set = new LinkedHashSet<>();

    private ImmutableSet(@NonNull Set<T> set) {
        if (!set.isEmpty()) {
            this.set.addAll(set);
        }
    }

    public Set<T> snapshot() {
        final LinkedHashSet<T> set = new LinkedHashSet<>();
        if (!this.set.isEmpty()) {
            set.addAll(this.set);
        }
        return set;
    }

    public static <T> ImmutableSet<T> of(@NonNull Set<T> set) {
        return new ImmutableSet<>(set);
    }
}