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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 to_native_string(string, encoding='ascii'):
 """ Given a string object, regardless of type, returns a representation of that string in the native string type, encoding and decoding where necessary. This assumes ASCII unless told otherwise. """

    out = None

    if isinstance(string, builtin_str):
        out = string
    else:
        if is_py2:
            out = string.encode(encoding)
        else:
            out = string.decode(encoding)

    return out