docs: def _filtered(self, text):
          '''
          Tests if a string should be filtered out or not.
  
          @text - The string to check against filter rules.
  
          Returns True if the string should be filtered out, i.e., not displayed.
          Returns False if the string should be displayed.
          '''
          filtered = None
          # Text is converted to lower case first, partially for historical
          # purposes, but also because it simplifies writing filter rules
          # (e.g., don't have to worry about case sensitivity).
          text = text.lower()
  
          for include in self.includes:
              if include.search(text):
                  filtered = False
                  break
  
          # If exclusive include filters have been specified and did
          # not match the text, then the text should be filtered out.
          if self.includes and filtered == None:
              return True
  
          for exclude in self.excludes:
              if exclude.search(text):
                  filtered = True
                  break
  
          # If no explicit exclude filters were matched, then the
          # text should *not* be filtered.
          if filtered == None:
              filtered = False
  
          return filtered