### Question:
FactorialHelper { @Nonnull public static BigInteger getAnyFactorialLinear (@Nonnegative final int n) { return new FactorialSplit ().getFactorial (n); } private  FactorialHelper(); @Nonnegative static long getSmallFactorial(@Nonnegative final int n); @Nonnull static BigInteger getAnyFactorialLinear(@Nonnegative final int n); static final int PREDEFINED_MIN_INDEX; static final int PREDEFINED_MAX_INDEX; }### Answer:
@Test @SuppressFBWarnings ("TQ_NEVER_VALUE_USED_WHERE_ALWAYS_REQUIRED") public void testGetAnyFactorialLinear () { final BigInteger y = FactorialHelper.getAnyFactorialLinear (FactorialHelper.PREDEFINED_MAX_INDEX + 1); assertEquals (FactorialHelper.getAnyFactorialLinear (FactorialHelper.PREDEFINED_MAX_INDEX) .multiply (BigInteger.valueOf (FactorialHelper.PREDEFINED_MAX_INDEX + 1L)), y); final BigInteger z = FactorialHelper.getAnyFactorialLinear (FactorialHelper.PREDEFINED_MAX_INDEX + 2); assertEquals (FactorialHelper.getAnyFactorialLinear (FactorialHelper.PREDEFINED_MAX_INDEX) .multiply (BigInteger.valueOf (FactorialHelper.PREDEFINED_MAX_INDEX + 1L)) .multiply (BigInteger.valueOf (FactorialHelper.PREDEFINED_MAX_INDEX + 2L)), z); try { FactorialHelper.getAnyFactorialLinear (-1); fail (); } catch (final IllegalArgumentException ex) {} }