### Question:
IntegerValueParser implements SingleLineValueParser<Integer> { @Override public Integer parse(final String... columns) { checkNotNull(columns, "No columns to parse from"); checkArgument(columns.length == 1, String.format("Expecting only one column, but got %d", columns.length)); final String value = columns[0]; checkArgument(!isNullOrEmpty(value), "Missing value to parse from"); return Integer.parseInt(value); } private  IntegerValueParser(); @Override Integer parse(final String... columns); static IntegerValueParser getDefault();  }### Answer:
@Test public void testParseFromValid() { assertEquals(10, PARSER.parse("10").intValue()); }
@Test(expected = NumberFormatException.class) public void testParseFromInvalid() { PARSER.parse("asdfg"); }
@Test(expected = IllegalArgumentException.class) public void testParseFromBlank() { PARSER.parse(""); }
@Test(expected = IllegalArgumentException.class) public void testParseFromNull() { PARSER.parse(); }