docs: 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