@Test
public void testOperationExecution() {

    // GIVEN
    final Document data = new Document().append(USER_DEFINED_COLLECTION_NAME_1, Arrays.asList(new Document()))
            .append(USER_DEFINED_COLLECTION_NAME_2, Arrays.asList(new Document()));
    // WHEN
    operation.execute(connection, data);
    // THEN
    final ArgumentCaptor<String> collectionNameCaptor = ArgumentCaptor.forClass(String.class);
    verify(connection, times(2)).getCollection(collectionNameCaptor.capture());
    final List<String> capturedCollectionNames = collectionNameCaptor.getAllValues();
    assertThat(capturedCollectionNames.size(), equalTo(2));
    assertThat(capturedCollectionNames, hasItems(USER_DEFINED_COLLECTION_NAME_1, USER_DEFINED_COLLECTION_NAME_2));
    verify(collection, times(2)).deleteMany(eq(new Document()));
}