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

    return out
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.
    
product/gradle-plugin/src/main/python/pip/_vendor/requests/_internal_utils.py