Functions { public static LongFunction identityLongFunction() { return identityLongFunction; } private  Functions(); static Function identityFunction(); static DoubleFunction identityDoubleFunction(); static DoubleFunction incDoubleFunction(); static IntFunction identityIntFunction(); static LongFunction identityLongFunction(); static IntFunction incIntFunction(); static IntFunction decIntFunction(); static LongFunction incLongFunction(); static LongFunction decLongFunction(); static IntFunction incIntFunction(int amount); static BooleanFunction inverseBooleanFunction(); static BooleanFunction identityBooleanFunction(); static LongFunction incLongFunction(long amount);  }
@Test public void testLongIdentityFunction() { LongFunction function = identityLongFunction(); assertEquals(0, function.call(0)); assertEquals(10, function.call(10)); assertEquals(-10, function.call(-10)); }