def init_app(self, app):
self.algorithm = app.config.get('<STR_LIT>', '<STR_LIT>')<EOL>if self.algorithm not in algs:<EOL><INDENT>raise ValueError('<STR_LIT>'.format(self.algorithm, algs))<EOL><DEDENT>self.rounds = app.config.get('<STR_LIT>', <NUM_LIT:1>)<EOL>if not isinstance(self.rounds, int):<EOL><INDENT>raise TypeError('<STR_LIT>')<EOL><DEDENT>
Initializes the Flask application with this extension. It grabs
        the necessary configuration values from ``app.config``, those being
        HASHING_METHOD and HASHING_ROUNDS. HASHING_METHOD defaults to ``sha256``
        but can be any one of ``hashlib.algorithms``. HASHING_ROUNDS specifies
        the number of times to hash the input with the specified algorithm.
        This defaults to 1.

        :param app: Flask application object