@Test
public void getTotalAmount() {

    assertNull(new OcrResponseParser(null).getTotalAmount());
    assertNull(new OcrResponseParser(new OcrResponse(null, null, null, null, null, null, null, null)).getTotalAmount());
    assertNull(new OcrResponseParser(new OcrResponse(new OcrResponseField<>(null, null), null, null, null, null, null, null, null)).getTotalAmount());
    assertEquals("23.30", new OcrResponseParser(new OcrResponse(new OcrResponseField<>(23.3, null), null, null, null, null, null, null, null)).getTotalAmount());
}