Streamdata: how to set size for generated data

Hi all, I am running property tests and was wondering how to set the size of the data generated. For example in JS you can do this :

describe("when a & b are arbitrary json objects; patch(a, diff(a,b)) == b", function () {
  it("holds for lots of small objects", function () {
    jsc.assert(property, { tests: 100, size: 50, quiet: false });
  });

Which would be running 100 tests and the data generated would be of size 50. I have this right now:

property "when a & b are arbitrary json objects; patch(a, diff(a,b)) == b" do
    check all(
            map_a <- map_of(one_of([string(:printable), atom(:alphanumeric)]), term()),
            map_b <- map_of(one_of([string(:printable), atom(:alphanumeric)]), term()),

            max_runs: 100,
            initial_size: 1,
            max_generation_size: 50
          ) do
      




     assert map_b == JsonDiffEx.patch(map_a,JsonDiffEx.diff(map_a, map_b))

Is this working the same way ? If not, what should be done? Thank you in advance, and patience with me.