def METHOD_NAME():
    operations = {
        "query": "mutation($a: [Upload!]!, $b: Upload!) { mixed(a: $a, b: $b) { id } }",
        "variables": {"a": [None, None], "b": None},
    }
    files_map = {"0": ["variables.a.0"], "1": ["variables.a.1", "variables.b"]}
    file0 = BytesIO()
    file1 = BytesIO()
    files = {"0": file0, "1": file1}
    result = replace_placeholders_with_files(operations, files_map, files)
    assert result["query"] == operations["query"]
    assert result["variables"]["a"][0] == file0
    assert result["variables"]["a"][1] == file1
    assert result["variables"]["b"] == file1