How to use the pyscaffold.api.helpers.merge function in PyScaffold

def add_files(struct, opts):
        struct = helpers.ensure(struct, "proj/tests/extra.file", "content")
        struct = helpers.merge(struct, {"proj": {"tests": {"another.file": "content"}}})

        return struct, opts

def test_merge_basics():
    # Given an existing structure,
    structure = {"a": {"b": {"c": "1", "d": "2"}}}
    # when it is merged to another structure with some common folder
    extra_files = {"a": {"b": {"c": "0"}, "e": "2"}, "f": {"g": {"h": "0"}}}
    structure = helpers.merge(structure, extra_files)
    # then the result, should contain both files from the original and the
    # merged structure,
    assert structure["a"]["b"]["d"] == "2"
    assert structure["f"]["g"]["h"] == "0"
    assert structure["a"]["e"] == "2"
    # the common leaves should be overridden and a tuple (content, rule)
    assert structure["a"]["b"]["c"] == "0"

def add_files(struct, opts):
        nov, ncr = helpers.NO_OVERWRITE, helpers.NO_CREATE
        struct = helpers.ensure(struct, "proj/tests/file0", "new")
        struct = helpers.ensure(struct, "proj/tests/file1", "new", nov)
        struct = helpers.ensure(struct, "proj/tests/file2", "new", ncr)
        struct = helpers.merge(
            struct,
            {
                "proj": {
                    "tests": {
                        "file3": ("new", nov),
                        "file4": ("new", ncr),
                        "file5": ("new", None),
                        "file6": "new",
                    }
                }
            },
        )

        return struct, opts

def test_merge_rules_just_in_original():
    # When an update rule exists in the original structure,
    structure = {"a": {"b": ("0", helpers.NO_CREATE)}}
    # but not in the merged,
    extra_files = {"a": {"b": "3"}}
    structure = helpers.merge(structure, extra_files)
    # then just the content should be updated
    # and the rule should be kept identical
    assert structure["a"]["b"] == ("3", helpers.NO_CREATE)

def test_merge_rules_just_in_merged():
    # When an update rule does not exist in the original structure,
    structure = {"a": {"b": "0"}}
    # but exists in the merged,
    extra_files = {"a": {"b": (None, helpers.NO_CREATE)}}
    structure = helpers.merge(structure, extra_files)
    # then just the rule should be updated
    # and the content should be kept identical
    assert structure["a"]["b"] == ("0", helpers.NO_CREATE)

def test_empty_string_leads_to_empty_file_during_merge():
    # When the original structure contains a leaf,
    structure = {"a": {"b": "0"}}
    # and the merged structure overrides it with an empty content
    extra_files = {"a": {"b": ""}}
    structure = helpers.merge(structure, extra_files)
    # then the resulting content should exist and be empty
    assert structure["a"]["b"] == ""