How to use the ipyleaflet.leaflet.Control function in ipyleaflet

self._add_unit(name, factor, decimals)

    def add_area_unit(self, name, factor, decimals=0):
        self._area_units.append(name)
        self._add_unit(name, factor, decimals)

    def _add_unit(self, name, factor, decimals):
        self._custom_units_dict[name] = {
            'factor': factor,
            'display': name,
            'decimals': decimals
        }
        self._custom_units = dict(**self._custom_units_dict)


class SplitMapControl(Control):
    _view_name = Unicode('LeafletSplitMapControlView').tag(sync=True)
    _model_name = Unicode('LeafletSplitMapControlModel').tag(sync=True)

    left_layer = Union((Instance(Layer), List(Instance(Layer)))).tag(sync=True, **widget_serialization)
    right_layer = Union((Instance(Layer), List(Instance(Layer)))).tag(sync=True, **widget_serialization)

    @default('left_layer')
    def _default_left_layer(self):
        return TileLayer()

    @default('right_layer')
    def _default_right_layer(self):
        return TileLayer()

    def __init__(self, **kwargs):
        super(SplitMapControl, self).__init__(**kwargs)

self.send({'msg': 'clear_polygons'})

    def clear_circles(self):
        self.send({'msg': 'clear_circles'})

    def clear_circle_markers(self):
        self.send({'msg': 'clear_circle_markers'})

    def clear_rectangles(self):
        self.send({'msg': 'clear_rectangles'})

    def clear_markers(self):
        self.send({'msg': 'clear_markers'})


class ZoomControl(Control):
    _view_name = Unicode('LeafletZoomControlView').tag(sync=True)
    _model_name = Unicode('LeafletZoomControlModel').tag(sync=True)

    zoom_in_text = Unicode('+').tag(sync=True, o=True)
    zoom_in_title = Unicode('Zoom in').tag(sync=True, o=True)
    zoom_out_text = Unicode('-').tag(sync=True, o=True)
    zoom_out_title = Unicode('Zoom out').tag(sync=True, o=True)


class AttributionControl(Control):
    _view_name = Unicode('LeafletAttributionControlView').tag(sync=True)
    _model_name = Unicode('LeafletAttributionControlModel').tag(sync=True)

    prefix = Unicode('Leaflet').tag(sync=True, o=True)

def __add__(self, item):
        if isinstance(item, Layer):
            self.add_layer(item)
        elif isinstance(item, Control):
            self.add_control(item)
        return self

options = List(trait=Unicode()).tag(sync=True)

    position = Enum(
        ['topright', 'topleft', 'bottomright', 'bottomleft'],
        default_value='topleft',
        help="""Possible values are topleft, topright, bottomleft
                or bottomright"""
    ).tag(sync=True, o=True)

    @default('options')
    def _default_options(self):
        return [name for name in self.traits(o=True)]


class WidgetControl(Control):
    _view_name = Unicode('LeafletWidgetControlView').tag(sync=True)
    _model_name = Unicode('LeafletWidgetControlModel').tag(sync=True)

    widget = Instance(DOMWidget).tag(sync=True, **widget_serialization)

    max_width = Int(default_value=None, allow_none=True).tag(sync=True)
    min_width = Int(default_value=None, allow_none=True).tag(sync=True)
    max_height = Int(default_value=None, allow_none=True).tag(sync=True)
    min_height = Int(default_value=None, allow_none=True).tag(sync=True)


class FullScreenControl(Control):
    _view_name = Unicode('LeafletFullScreenControlView').tag(sync=True)
    _model_name = Unicode('LeafletFullScreenControlModel').tag(sync=True)

return [name for name in self.traits(o=True)]


class WidgetControl(Control):
    _view_name = Unicode('LeafletWidgetControlView').tag(sync=True)
    _model_name = Unicode('LeafletWidgetControlModel').tag(sync=True)

    widget = Instance(DOMWidget).tag(sync=True, **widget_serialization)

    max_width = Int(default_value=None, allow_none=True).tag(sync=True)
    min_width = Int(default_value=None, allow_none=True).tag(sync=True)
    max_height = Int(default_value=None, allow_none=True).tag(sync=True)
    min_height = Int(default_value=None, allow_none=True).tag(sync=True)


class FullScreenControl(Control):
    _view_name = Unicode('LeafletFullScreenControlView').tag(sync=True)
    _model_name = Unicode('LeafletFullScreenControlModel').tag(sync=True)


class LayersControl(Control):
    _view_name = Unicode('LeafletLayersControlView').tag(sync=True)
    _model_name = Unicode('LeafletLayersControlModel').tag(sync=True)


class MeasureControl(Control):
    _view_name = Unicode('LeafletMeasureControlView').tag(sync=True)
    _model_name = Unicode('LeafletMeasureControlModel').tag(sync=True)

    _length_units = ['feet', 'meters', 'miles', 'kilometers']
    _area_units = ['acres', 'hectares', 'sqfeet', 'sqmeters', 'sqmiles']
    _custom_units_dict = {}

def remove_layer(self, layer):
        if layer.model_id not in self._layer_ids:
            raise LayerException('layer not on map: %r' % layer)
        self.layers = tuple([l for l in self.layers if l.model_id != layer.model_id])

    def substitute_layer(self, old, new):
        if isinstance(new, dict):
            new = basemap_to_tiles(new)
        if old.model_id not in self._layer_ids:
            raise LayerException('Could not substitute layer: layer not on map.')
        self.layers = tuple([new if l.model_id == old.model_id else l for l in self.layers])

    def clear_layers(self):
        self.layers = ()

    controls = Tuple().tag(trait=Instance(Control), sync=True, **widget_serialization)
    _control_ids = List()

    @validate('controls')
    def _validate_controls(self, proposal):
        '''Validate controls list.

        Makes sure only one instance of any given layer can exist in the
        controls list.
        '''
        self._control_ids = [c.model_id for c in proposal.value]
        if len(set(self._control_ids)) != len(self._control_ids):
            raise ControlException('duplicate control detected, only use each control once')
        return proposal.value

    def add_control(self, control):
        if control.model_id in self._control_ids:

def clear_markers(self):
        self.send({'msg': 'clear_markers'})


class ZoomControl(Control):
    _view_name = Unicode('LeafletZoomControlView').tag(sync=True)
    _model_name = Unicode('LeafletZoomControlModel').tag(sync=True)

    zoom_in_text = Unicode('+').tag(sync=True, o=True)
    zoom_in_title = Unicode('Zoom in').tag(sync=True, o=True)
    zoom_out_text = Unicode('-').tag(sync=True, o=True)
    zoom_out_title = Unicode('Zoom out').tag(sync=True, o=True)


class AttributionControl(Control):
    _view_name = Unicode('LeafletAttributionControlView').tag(sync=True)
    _model_name = Unicode('LeafletAttributionControlModel').tag(sync=True)

    prefix = Unicode('Leaflet').tag(sync=True, o=True)


class MapStyle(Style, Widget):
    """ Map Style Widget """
    _model_name = Unicode('LeafletMapStyleModel').tag(sync=True)
    _model_module = Unicode("jupyter-leaflet").tag(sync=True)

    _model_module_version = Unicode(EXTENSION_VERSION).tag(sync=True)

    cursor = Enum(values=allowed_cursor, default_value='grab').tag(sync=True)

_model_name = Unicode('LeafletWidgetControlModel').tag(sync=True)

    widget = Instance(DOMWidget).tag(sync=True, **widget_serialization)

    max_width = Int(default_value=None, allow_none=True).tag(sync=True)
    min_width = Int(default_value=None, allow_none=True).tag(sync=True)
    max_height = Int(default_value=None, allow_none=True).tag(sync=True)
    min_height = Int(default_value=None, allow_none=True).tag(sync=True)


class FullScreenControl(Control):
    _view_name = Unicode('LeafletFullScreenControlView').tag(sync=True)
    _model_name = Unicode('LeafletFullScreenControlModel').tag(sync=True)


class LayersControl(Control):
    _view_name = Unicode('LeafletLayersControlView').tag(sync=True)
    _model_name = Unicode('LeafletLayersControlModel').tag(sync=True)


class MeasureControl(Control):
    _view_name = Unicode('LeafletMeasureControlView').tag(sync=True)
    _model_name = Unicode('LeafletMeasureControlModel').tag(sync=True)

    _length_units = ['feet', 'meters', 'miles', 'kilometers']
    _area_units = ['acres', 'hectares', 'sqfeet', 'sqmeters', 'sqmiles']
    _custom_units_dict = {}
    _custom_units = Dict().tag(sync=True)

    primary_length_unit = Enum(
        values=_length_units,
        default_value='feet',

    @default('right_layer')
    def _default_right_layer(self):
        return TileLayer()

    def __init__(self, **kwargs):
        super(SplitMapControl, self).__init__(**kwargs)
        self.on_msg(self._handle_leaflet_event)

    def _handle_leaflet_event(self, _, content, buffers):
        if content.get('event', '') == 'dividermove':
            event = content.get('event')
            self.x = event.x


class DrawControl(Control):
    _view_name = Unicode('LeafletDrawControlView').tag(sync=True)
    _model_name = Unicode('LeafletDrawControlModel').tag(sync=True)

    # Enable each of the following drawing by giving them a non empty dict of options
    # You can add Leaflet style options in the shapeOptions sub-dict
    # See https://github.com/Leaflet/Leaflet.draw#polylineoptions
    # TODO: mutable default value!
    polyline = Dict({'shapeOptions': {}}).tag(sync=True)
    # See https://github.com/Leaflet/Leaflet.draw#polygonoptions
    # TODO: mutable default value!
    polygon = Dict({'shapeOptions': {}}).tag(sync=True)
    circlemarker = Dict({'shapeOptions': {}}).tag(sync=True)

    # Leave empty to disable these
    circle = Dict().tag(sync=True)
    rectangle = Dict().tag(sync=True)

min_width = Int(default_value=None, allow_none=True).tag(sync=True)
    max_height = Int(default_value=None, allow_none=True).tag(sync=True)
    min_height = Int(default_value=None, allow_none=True).tag(sync=True)


class FullScreenControl(Control):
    _view_name = Unicode('LeafletFullScreenControlView').tag(sync=True)
    _model_name = Unicode('LeafletFullScreenControlModel').tag(sync=True)


class LayersControl(Control):
    _view_name = Unicode('LeafletLayersControlView').tag(sync=True)
    _model_name = Unicode('LeafletLayersControlModel').tag(sync=True)


class MeasureControl(Control):
    _view_name = Unicode('LeafletMeasureControlView').tag(sync=True)
    _model_name = Unicode('LeafletMeasureControlModel').tag(sync=True)

    _length_units = ['feet', 'meters', 'miles', 'kilometers']
    _area_units = ['acres', 'hectares', 'sqfeet', 'sqmeters', 'sqmiles']
    _custom_units_dict = {}
    _custom_units = Dict().tag(sync=True)

    primary_length_unit = Enum(
        values=_length_units,
        default_value='feet',
        help="""Possible values are feet, meters, miles, kilometers or any user
                defined unit"""
    ).tag(sync=True, o=True)

    secondary_length_unit = Enum(