The best part of the holy trait pattern is that we can use it with any object, even when its type belongs to a different abstract type hierarchy. Let's explore the case of literature, where we may define its own type hierarchy as follows:

abstract type Literature end

struct Book <: Literature
    name
end

Now, we can make it obey the LiquidityStyle trait, as follows:

# assign trait
LiquidityStyle(::Type{Book}) = IsLiquid()

# sample pricing function
marketprice(b::Book) = 10.0

Now, we can trade books, just like other tradable assets.