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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 _clear(self):
        '''Clear state.
        '''
        self._depth     = 0   # recursion depth
        self._duplicate = 0
        self._incl      = ''  # or ' (incl. code)'
        self._missed    = 0   # due to errors
        self._profile   = False
        self._profs     = {}
        self._seen      = {}
        self._total     = 0   # total size
        for k in _keys(self._excl_d):
            self._excl_d[k] = 0