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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 get_book_metadata(self, asin):
 """Returns a book's metadata. Args: asin: The ASIN of the book to be queried. Returns: A `KindleBook` instance corresponding to the book associated with `asin`. """

    kbm = self._get_api_call('get_book_metadata', '"%s"' % asin)
    return KindleCloudReaderAPI._kbm_to_book(kbm)