### Question:
ParseString implements IsParser<String> { @Override public String parse(Object o, Field field) { return isValid(o) ? String.valueOf(o.toString()) : null; }  @Override String parse(Object o, Field field); @Override void setCell(String o, Cell cell, Field field);  }### Answer:
@Test public void parse() throws Exception { String actual = parseString.parse(null, null); assertEquals(null, actual); actual = parseString.parse(expected, null); assertEquals(expected, actual); }