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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 _conflicting_defaults(typename, conflicts):
 """Format an error message for conflicting default implementations. Parameters typename : str Name of the type for which we're producing an error. conflicts : dict[str -> list[Interface]] Map from strings to interfaces providing a default with that name. Returns ------- message : str User-facing error message. """

    message = "\nclass {C} received conflicting default implementations:".format(
        C=typename,
    )
    for attrname, interfaces in conflicts.items():
        message += dedent(
            """

            The following interfaces provided default implementations for {attr!r}:
            {interfaces}"""
        ).format(
            attr=attrname,
            interfaces=bulleted_list(sorted(map(getname, interfaces))),
        )
    return InvalidImplementation(message)