How to use the flax.entity.Layer function in flax

PlayerIntelligence,
    Render(sprite=Sprite.player, color='player'),
    name='you',
)
Salamango = Creature(
    Combatant(strength=1, health=5),
    GenericAI,
    Render(sprite=Sprite.lizard, color='salamango'),
    name='salamango',
)


# -----------------------------------------------------------------------------
# Items

Item = partial(EntityType, Portable, layer=Layer.item)

Key = Item(Render(sprite=Sprite.key, color='default'), name='key')

Gem = Item(Render(sprite=Sprite.gem, color='default'), name='gemstone')
Crown = Item(Render(sprite=Sprite.crown, color='gold'), name='crown')

# TODO implement a potion!
# Potion = Item(UsablePotion, name='potion', tmp_rendering=('ð', 'default'))
Potion = Item(
    Render(sprite=Sprite.flask, color='default'),
    name='potion',
)

Crate = Item(
    Container,
    Render(sprite=Sprite.crate, color='wood'),

def do_pick_up(event, portable):
    from flax.entity import Layer
    assert portable.entity.type.layer is Layer.item
    event.world.current_map.remove(portable.entity)
    IContainer(event.actor).inventory.append(portable.entity)

# ⇭ gravestone
    # ⇶ ammo
    # ⤊ cabin?  uggh too wide barely


class Material(Enum):
    pass


###############################################################################
# From here on it's all just definitions of specific types.

# -----------------------------------------------------------------------------
# Architecture

Architecture = partial(EntityType, layer=Layer.architecture)

StairsDown = Architecture(
    Empty,
    PortalDownstairs,
    Render(sprite=Sprite.stairs_down, color='stairs'),
    name='stairs',
)
StairsUp = Architecture(
    Empty,
    PortalUpstairs,
    Render(sprite=Sprite.stairs_up, color='stairs'),
    name='stairs',
)
Ladder = Architecture(
    Empty,
    PortalUpstairs,

def attach(self, entity):
        """Add the given entity from this tile.  Its position is not affected.
        This method is only intended to be called by the map object.
        """
        if entity.layer is Layer.architecture:
            assert self.architecture is None
            self.architecture = entity
        elif entity.layer is Layer.item:
            self.items.append(entity)
        elif entity.layer is Layer.creature:
            assert self.creature is None
            self.creature = entity
        else:
            raise TypeError(
                "Unknown layer {!r} for entity {!r}"
                .format(entity.layer, entity))

def detach(self, entity):
        """Remove the given entity from this tile.  Its position is not
        affected.  This method is only intended to be called by the map object.
        """
        if entity.layer is Layer.architecture:
            assert self.architecture is entity
            self.architecture = None
        elif entity.layer is Layer.item:
            self.items.remove(entity)
        elif entity.layer is Layer.creature:
            assert self.creature is entity
            self.creature = None
        else:
            raise TypeError(
                "Unknown layer {!r} for entity {!r}"
                .format(entity.layer, entity))

(1, Sprite.ruin4b, 'decay3'),
        (1, Sprite.ruin4c, 'decay3'),
        (1, Sprite.ruin4d, 'decay3'),
        (5, Sprite.ruin3a, 'decay2'),
        (5, Sprite.ruin3b, 'decay2'),
        (3, Sprite.ruin2, 'decay1'),
        (10, Sprite.ruin1e, 'decay0'),
    ),
    name='ruin',
)


# -----------------------------------------------------------------------------
# Creatures

Creature = partial(EntityType, Solid, Container, Bodied, layer=Layer.creature)
Player = Creature(
    Combatant(strength=3, health=20),
    PlayerIntelligence,
    Render(sprite=Sprite.player, color='player'),
    name='you',
)
Salamango = Creature(
    Combatant(strength=1, health=5),
    GenericAI,
    Render(sprite=Sprite.lizard, color='salamango'),
    name='salamango',
)


# -----------------------------------------------------------------------------
# Items