### Question:
CurrencyPair { public boolean containsCcy(final String ccy) { return ccy1.equalsIgnoreCase(StringUtil.toUpperCase(ccy)) || ccy2.equalsIgnoreCase(StringUtil.toUpperCase(ccy)); } CurrencyPair(final String ccy1, final String ccy2); static CurrencyPair of(final String ccy1, final String ccy2); String getCcy1(); String getCcy2(); @Override int hashCode(); @Override boolean equals(final Object obj); @Override String toString(); boolean containsCcy(final String ccy); Optional<String> findCommonCcy(final CurrencyPair otherPair); CurrencyPair createInverse();  }### Answer:
@Test public void testContainsCcy() throws Exception { final CurrencyPair cp = new CurrencyPair("A", "B"); assertThat(cp.containsCcy("A")).isTrue(); assertThat(cp.containsCcy("B")).isTrue(); assertThat(cp.containsCcy("C")).isFalse(); }