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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 process_tokens(self, tokens):
 """Process the token stream. This is required to override the parent class' implementation. Args: tokens: the tokens from the token stream to process. """

        for tok_type, token, (start_row, start_col), _, _ in tokens:
            if tok_type == tokenize.STRING:
                # 'token' is the whole un-parsed token; we can look at the start
                # of it to see whether it's a raw or unicode string etc.
                self._process_string_token(token, start_row, start_col)