def METHOD_NAME(self, property, css, native=None, selector=".toga"):
    """Apply a CSS style controlling a specific property type.
    GTK controls appearance with CSS; each GTK widget can have an
    independent style sheet, composed out of multiple providers.
    Toga uses a separate provider for each property that needs to be
    controlled (e.g., color, font, ...). When that property is modified, the
    old provider for that property is removed; if new CSS has been provided,
    a new provider is constructed and added to the widget.
    It is assumed that every Toga widget will have the class ``toga``.
    :param property: The style property to modify
    :param css: A dictionary of string key-value pairs, describing the new
        CSS for the given property. If ``None``, the Toga style for that
        property will be reset
    :param native: The native widget to which the style should be applied.
        Defaults to ``self.native``.
    :param selector: The CSS selector used to target the style. Defaults to
        ``.toga``.
    """
    if native is None:
        native = self.native
    style_context = native.get_style_context()
    style_provider = self.style_providers.pop((property, id(native)), None)
    # If there was a previous style provider for the given property, remove
    # it from the GTK widget
    if style_provider:
        style_context.remove_provider(style_provider)
    # If there's new CSS to apply, construct a new provider, and install it.
    if css is not None:
        # Create a new CSS StyleProvider
        style_provider = Gtk.CssProvider()
        styles = " ".join(f"{key}: {value};" for key, value in css.items())
        declaration = selector + " {" + styles + "}"
        style_provider.load_from_data(declaration.encode())
        # Add the provider to the widget
        style_context.add_provider(
            style_provider,
            Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION,
        )
        # Store the provider so it can be removed later
        self.style_providers[(property, id(native))] = style_provider