@Override
public String nextLine() {
Key key = null;
if (effectiveDateToFilterFor == null) {
if (iterator.hasNext()) {
key = iterator.next();
}
} else {
while (key == null && iterator.hasNext()) {
Key unfilteredKey = iterator.next();
if (effectiveDateToFilterFor.equals(unfilteredKey.getDate())) {
key = unfilteredKey;
}
}
}
if (key != null) {
return formatLine(key);
} else {
return null;
}
}
private String formatLine(Key key) {
return String.format(FORMAT, key.getIdString(), key.getDate(), table.get(key));
}