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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def concatenate(input_files, output_file):
 """ Concatenates the input files into the single output file. In debug mode this function adds a comment with the filename before the contents of each file. """

    from .modules import utils, concat

    if not isinstance(input_files, (list, tuple)):
        raise RuntimeError('Concatenate takes a list of input files.')

    return {
        'dependencies_fn': utils.no_dependencies,
        'compiler_fn': concat.concatenate_input_files,
        'input': input_files,
        'output': output_file,
        'kwargs': {},
    }