Calls a custom function which must create the output file.

    The custom function takes 3 parameters: ``input_files``,
    ``output_file`` and a boolean ``release``.

def custom_function(func, input_files, output_file):
    """
    Calls a custom function which must create the output file.

    The custom function takes 3 parameters: ``input_files``,
    ``output_file`` and a boolean ``release``.
    """
    from .modules import utils

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