### Question:
BigIntegerConverter implements TypeConverter<BigInteger> { public BigInteger convert(Integer i) { return new BigInteger(i.toString()); } BigIntegerConverter(); BigInteger convert(Integer i); BigInteger convert(Long l); BigInteger convert(Double dob); BigInteger convert(BigDecimal bd); BigInteger convert(String v);  }### Answer:
@Test public void Integerからのconvertテスト() { Integer i = 255; BigInteger expected = new BigInteger("255"); BigInteger actual = new BigIntegerConverter().convert(i); assertEquals(expected, actual); }
@Test public void Longからのconvertテスト() { Long i = 255L; BigInteger expected = new BigInteger("255"); BigInteger actual = new BigIntegerConverter().convert(i); assertEquals(expected, actual); }
@Test public void BigDecimalからのconvertテスト() { BigDecimal i = new BigDecimal(255); BigInteger expected = new BigInteger("255"); BigInteger actual = new BigIntegerConverter().convert(i); assertEquals(expected, actual); }
@Test public void Stringからのconvertテスト1() { String s = "255"; BigInteger expected = new BigInteger("255"); BigInteger actual = new BigIntegerConverter().convert(s); assertEquals(expected, actual); }
@Test public void Stringからのconvertテスト2() { String s = null; BigInteger expected = null; BigInteger actual = new BigIntegerConverter().convert(s); assertEquals(expected, actual); }
@Test public void Stringからのconvertテスト3() { String s = ""; BigInteger expected = null; BigInteger actual = new BigIntegerConverter().convert(s); assertEquals(expected, actual); }