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aswil.entities.exist(category_name, entity_name)

Given the name of an entity and his category name, will return the entity prototype if exist
false(boolean) otherwise.
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aswil.entities.getEntity(category_name, entity_name)

Wrapper function of aswil.entities.exist(category_name, entity_name).
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aswil.entities.removeCollisionMaskOnEntity(category_name, entity_name, to_remove_mask_name)

Given entity name and his category name, will remove the mask indicated with the name
from the collosion layer of entity.
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aswil.entities.addCollisionMaskOnEntity(category_name, entity_name, mask_name)

Given entity name and his category name, will add the mask indicated by the name
into collosion layer of entity.
If the entity don't have a collision_mask table well setted, will apply this mask =
{"item-layer", "object-layer", "player-layer", "water-tile", to_add_mask_name}
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