map.put("ケ", new String[] { "ke" });
        map.put("コ", new String[] { "ko" });

        map.put("サ", new String[] { "sa" });
        map.put("シ", new String[] { "si", "shi" });
        map.put("ス", new String[] { "su" });
        map.put("セ", new String[] { "se" });
        map.put("ソ", new String[] { "so" });

        map.put("タ", new String[] { "ta" });

    assertThrows(IllegalArgumentException.class, () -> japaneseToSpanish.apply("Ni"));
    assertEquals("Tres", japaneseToSpanish.apply("San"));
    assertThrows(IllegalArgumentException.class, () -> japaneseToSpanish.apply("Shi"));

    new EqualsTester()
        .addEqualityGroup(japaneseToSpanish, Functions.compose(integerToSpanish, japaneseToInteger))
        .addEqualityGroup(japaneseToInteger)
        .addEqualityGroup(integerToSpanish)

    assertThrows(IllegalArgumentException.class, () -> japaneseToSpanish.apply("Ni"));
    assertEquals("Tres", japaneseToSpanish.apply("San"));
    assertThrows(IllegalArgumentException.class, () -> japaneseToSpanish.apply("Shi"));

    new EqualsTester()
        .addEqualityGroup(japaneseToSpanish, Functions.compose(integerToSpanish, japaneseToInteger))
        .addEqualityGroup(japaneseToInteger)
        .addEqualityGroup(integerToSpanish)

Puzovic, mohantym, Nathan John Sircombe, Nathan Luehr, Nilesh Agarwalla, Patrice Vignola, peterjc123, Philip Turner, Rajeshwar Reddy T, Robert Kalmar, Rodrigo Formigone, Rohit Santhanam, rui, Sachin Muradi, Saduf2019, sandip, Scott Leishman, Serge Panev, Shi,Guangyong, Srinivasan Narayanamoorthy, stanley, Steven I Reeves, stevenireeves, sushreebarsa, Tamas Bela Feher, Tao He, Thomas Schmeyer, Tiago Almeida, Trevor Morris, Uday Bondhugula, Uwe L. Korn, Varghese, Jojimon, Vishnuvardhan Janapati, William Muir,...