### Question:
ManyToManyMap { public boolean isEmpty() { return lToRMappings.isEmpty(); } ManyToManyMap();  ManyToManyMap(int initialCapacity);  ManyToManyMap(int initialCapacity, float loadFactor); void add(L left, R right); boolean remove(L left, R right); Set<R> removeAllMappingsForLeft(L left); Set<L> removeAllMappingsForRight(R right); Set<R> getRight(L left); Set<L> getLeft(R right); int size(); int numberOfmappingsForLeft(L left); int numberOfmappingsForRight(R right); boolean containsLeft(L left); boolean containsRight(R right); boolean isEmpty(); void clear(); Iterator<L> leftIterator(); Iterator<R> rightIterator(); @Override boolean equals(Object obj); @Override int hashCode(); @Override String toString();  }### Answer:
@Test public void testIsEmpty() { assertTrue(new ManyToManyMap<String, String>().isEmpty()); }