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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 _filter(self, text, context, encoding):
 """Filter JavaScript comments."""


        content = []
        self.current_encoding = encoding
        self.line_num = 1
        self.prev_line = -1
        self.leading = ''
        self.block_comments = []
        self.line_comments = []

        self.find_content(text)
        self.extend_src(content, context)

        return content