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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 is_cached(file_or_script):
 """Return True if file_or_script is cached"""

    if isinstance(file_or_script, str):
        return unmap_file(file_or_script) in file_cache
    else:
        return is_cached_script(file_or_script)
    return