PropCheck.BasicTypes.resize

You're seeing just the function resize, go back to PropCheck.BasicTypes module for more information.
Link to this function

resize(new_size, raw_type)

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Specs

resize(size(), raw_type()) :: type()

Overrides the size parameter used when generating instances of type with new_size.

Has no effect on size-less types, such as unions. Also, this will not affect the generation of any internal types contained in type, such as the elements of a list - those will still be generated using the test-wide value of size. One use of this function is to modify types to produce instances that grow faster or slower, like so:

iex> quickcheck(forall l <- list(integer()) do
...>   length(l) <= 42
...> end)
true

iex> long_list = sized(size, resize(size * 2, list(integer())))
iex> really_long = such_that_maybe l <- long_list, when:
...>      length(l) > 42
iex> quickcheck(forall l <- really_long do
...>   (length(l) <= 84)
...>   |> measure("List length", length l)
...>   |> collect(length l)
...> end)
true

The above specifies a list type that grows twice as fast as normal lists.