final String line = "TEST";
final FieldSet fs = new DefaultFieldSet(new String[]{"token1", "token2"});
final String item = "ITEM";
LineTokenizer tokenizer = mock(LineTokenizer.class);
when(tokenizer.tokenize(line)).thenReturn(fs);
@SuppressWarnings("unchecked")
FieldSetMapper<String> fsMapper = mock(FieldSetMapper.class);
when(fsMapper.mapFieldSet(fs)).thenReturn(item);