How to use the jupyter-innotater.jupyter_innotater.mixins.DataMixin function in jupyter-innotater

self.get_widget().observe(fn, names=names)

    def update_ui(self, uindex):
        raise Exception('Do not call update_ui on base class, Innotation {} with name {}'.format(type(self), self.name))

    def update_data(self, uindex):
        raise Exception('Do not call update_data on an input-only class, Innotation {} with name {}'.format(type(self), self.name))

    def contains_widget(self, widget):
        return self.get_widget() == widget

    def list_innotations_tree(self):
        return [self]


class ImageInnotation(Innotation, DataMixin):

    def __init__(self, *args, **kwargs):

        super().__init__(*args, **kwargs)

        self.width = kwargs.get('width', 0)
        self.height = kwargs.get('height', 0)
        self.path = kwargs.get('path', '')

        self.transform = kwargs.get('transform', None)

        self.annotation_styles = kwargs.get('annotation_styles', {})

        self.colorspace = 'BGR'
        if 'colorspace' in kwargs:
            self.colorspace = kwargs['colorspace']

self.max_repeats += 1
        self.get_widget().set_max_repeats(self.max_repeats)
        self.watchlist.add(Watcher(name=name, repeat_index=repeat_index))

    def get_current_watcher(self):
        return self.watchlist[self.get_widget().rect_index]

    def set_current_watcher(self, name, repeat_index):
        self.get_widget().rect_index = self.watchlist.get_watcher_index(name, repeat_index)

    def get_rect_for_watcher(self, name, repeat_index):
        watcher_index = self.watchlist.get_watcher_index(name, repeat_index)
        return self.get_widget().rects[watcher_index*4:(watcher_index+1)*4]


class BoundingBoxInnotation(Innotation, DataMixin):

    def __init__(self, *args, **kwargs):

        super().__init__(*args, **kwargs)

        self.source = kwargs.get('source', None)
        self.sourcedw = None

    def post_register(self, datamanager):
        if self.source is not None:
            self.sourcedw = datamanager.get_data_wrapper_by_name(self.source)

            if self.sourcedw is None:
                raise Exception('ImageInnotation named {} not found but specified as source attribute for BoundingBoxInnotation'.format(self.source))

            if not isinstance(self.sourcedw, ImageInnotation):

def rectIndexChanged(self, change):
        if self.sourcedw is not None:
            #if self.sourcedw.get_widget().rect_index == self.repeat_index:
            watcher = self.sourcedw.get_current_watcher()
            if watcher.name == self.name and watcher.repeat_index == self.repeat_index:
                self.get_widget().add_class('bounding-box-active')
            else:
                self.get_widget().remove_class('bounding-box-active')

    def widget_clicked(self, w):
        if self.sourcedw is not None:
            self.sourcedw.set_current_watcher(self.name, self.repeat_index)


class MultiClassInnotation(Innotation, DataMixin):

    def __init__(self, *args, **kwargs):

        super().__init__(*args, **kwargs)

        # Just a 1-dim array with values corresponding to class numbers e.g. 0-5
        self.datadepth = 'simple'

        self.dims = 1
        if hasattr(self._get_data(0), '__len__'):
            self.dims = 2

        if self.dims > 1:
            if len(self._get_data(0)) == 1:
                self.datadepth = 'colvector' # A column vector corresponding to class numbers directly
            else:

class BinaryClassInnotation(MultiClassInnotation):

    def _guess_classes(self):
        self.classes = ['False', 'True']

    def _create_widget(self):
        return Checkbox(description=self.desc, layout=self.layout, disabled=self.disabled)

    def update_ui(self, uindex):
        self.get_widget().value = bool(self._calc_class_index(uindex) == 1)

    def _get_widget_value(self):
        return self.classes[self.get_widget().value and 1 or 0]


class TextInnotation(Innotation, DataMixin):

    def __init__(self, *args, **kwargs):

        self.multiline = kwargs.get('multiline', True)

        super().__init__(*args, **kwargs)

    def _create_widget(self):
        if self.multiline:
            return Textarea(layout=self.layout, disabled=self.disabled)
        return Text(layout=self.layout, disabled=self.disabled)

    def update_ui(self, uindex):
        self.get_widget().value = str(self._get_data(uindex))

    def update_data(self, uindex):

def _add_to_alldws(self, dw, l):
        for onedw in dw.list_innotations_tree():
            name = onedw.name
            if name in self.alldws:
                raise Exception('Duplicate Innotation {}'.format(name))

            self.alldws[name] = onedw

        # Check number of rows is the same and not zero
        if isinstance(dw, DataMixin):
            this_len = len(dw)
            if l == -1:
                if this_len == 0:
                    raise Exception('Innotation {} {} has 0 data rows'.format(type(dw), name))
                l = this_len
            elif l != this_len:
                raise Exception('Innotations must all have same number of rows: {} {} has a different number of data rows than previous Innotations'.format(type(dw), name))

        return l