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

keep_in_view = Bool(False).tag(sync=True, o=True)
    close_button = Bool(True).tag(sync=True, o=True)
    auto_close = Bool(True).tag(sync=True, o=True)
    close_on_escape_key = Bool(True).tag(sync=True, o=True)
    class_name = Unicode('').tag(sync=True, o=True)


class RasterLayer(Layer):
    _view_name = Unicode('LeafletRasterLayerView').tag(sync=True)
    _model_name = Unicode('LeafletRasterLayerModel').tag(sync=True)

    opacity = Float(1.0, min=0.0, max=1.0).tag(sync=True)
    visible = Bool(True).tag(sync=True)


class TileLayer(RasterLayer):
    _view_name = Unicode('LeafletTileLayerView').tag(sync=True)
    _model_name = Unicode('LeafletTileLayerModel').tag(sync=True)

    bottom = Bool(True).tag(sync=True)
    url = Unicode('https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png').tag(sync=True)
    min_zoom = Int(0).tag(sync=True, o=True)
    max_zoom = Int(18).tag(sync=True, o=True)
    min_native_zoom = Int(0).tag(sync=True, o=True)
    max_native_zoom = Int(18).tag(sync=True, o=True)
    tile_size = Int(256).tag(sync=True, o=True)
    attribution = Unicode('Map data (c) <a href="https://openstreetmap.org">OpenStreetMap</a> contributors').tag(sync=True, o=True)
    detect_retina = Bool(False).tag(sync=True, o=True)
    no_wrap = Bool(False).tag(sync=True, o=True)
    tms = Bool(False).tag(sync=True, o=True)
    show_loading = Bool(False).tag(sync=True)
    loading = Bool(False, read_only=True).tag(sync=True)

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

    service = Unicode('WMS').tag(sync=True)
    request = Unicode('GetMap').tag(sync=True)
    version = Unicode('1.1.1').tag(sync=True)

    # Options
    layers = Unicode().tag(sync=True, o=True)
    styles = Unicode().tag(sync=True, o=True)
    format = Unicode('image/jpeg').tag(sync=True, o=True)
    transparent = Bool(False).tag(sync=True, o=True)
    crs = Enum(values=allowed_crs, default_value='EPSG3857').tag(sync=True)
    uppercase = Bool(False).tag(sync=True, o=True)


class ImageOverlay(RasterLayer):
    _view_name = Unicode('LeafletImageOverlayView').tag(sync=True)
    _model_name = Unicode('LeafletImageOverlayModel').tag(sync=True)

    url = Unicode().tag(sync=True)
    bounds = List([def_loc, def_loc], help='SW and NE corners of the image').tag(sync=True)

    # Options
    attribution = Unicode().tag(sync=True, o=True)


class VideoOverlay(RasterLayer):
    _view_name = Unicode('LeafletVideoOverlayView').tag(sync=True)
    _model_name = Unicode('LeafletVideoOverlayModel').tag(sync=True)

    url = Unicode().tag(sync=True)
    bounds = List([def_loc, def_loc], help='SW and NE corners of the image').tag(sync=True)

crs = Enum(values=allowed_crs, default_value='EPSG3857').tag(sync=True)
    uppercase = Bool(False).tag(sync=True, o=True)


class ImageOverlay(RasterLayer):
    _view_name = Unicode('LeafletImageOverlayView').tag(sync=True)
    _model_name = Unicode('LeafletImageOverlayModel').tag(sync=True)

    url = Unicode().tag(sync=True)
    bounds = List([def_loc, def_loc], help='SW and NE corners of the image').tag(sync=True)

    # Options
    attribution = Unicode().tag(sync=True, o=True)


class VideoOverlay(RasterLayer):
    _view_name = Unicode('LeafletVideoOverlayView').tag(sync=True)
    _model_name = Unicode('LeafletVideoOverlayModel').tag(sync=True)

    url = Unicode().tag(sync=True)
    bounds = List([def_loc, def_loc], help='SW and NE corners of the image').tag(sync=True)

    # Options
    attribution = Unicode().tag(sync=True, o=True)


class Velocity(Layer):
    _view_name = Unicode('LeafletVelocityView').tag(sync=True)
    _model_name = Unicode('LeafletVelocityModel').tag(sync=True)

    zonal_speed = Unicode('', help='Name of the zonal speed in the dataset')
    meridional_speed = Unicode('', help='Name of the meridional speed in the dataset')

"rgb(151,218,168)",
        "rgb(198,231,181)",
        "rgb(238,247,217)",
        "rgb(255,238,159)",
        "rgb(252,217,125)",
        "rgb(255,182,100)",
        "rgb(252,150,75)",
        "rgb(250,112,52)",
        "rgb(245,64,32)",
        "rgb(237,45,28)",
        "rgb(220,24,32)",
        "rgb(180,0,35)"
        ]).tag(sync=True, o=True)


class Heatmap(RasterLayer):
    _view_name = Unicode('LeafletHeatmapView').tag(sync=True)
    _model_name = Unicode('LeafletHeatmapModel').tag(sync=True)

    locations = List().tag(sync=True)

    # Options
    min_opacity = Float(0.05).tag(sync=True, o=True)
    max_zoom = Int(18).tag(sync=True, o=True)
    max = Float(1.0).tag(sync=True, o=True)
    radius = Float(25.0).tag(sync=True, o=True)
    blur = Float(15.0).tag(sync=True, o=True)
    gradient = Dict({0.4: 'blue', 0.6: 'cyan', 0.7: 'lime', 0.8: 'yellow', 1.0: 'red'}).tag(sync=True, o=True)


class VectorLayer(Layer):
    _view_name = Unicode('LeafletVectorLayerView').tag(sync=True)