code: def flatten_rules(self, declarations):
          
          rules = []
  
          for protocole, paths in declarations:
              # If there is a protocole (like 'url), drop it
              if protocole:
                  continue
              # Unquote and possibly split multiple rule in the same declaration
              rules.extend([self.strip_quotes(v.strip())
                            for v in paths.split(',')])
  
          return list(filter(self.filter_rules, rules))
docs: Flatten returned import rules from regex.
  
          Because import rules can contains multiple items in the same rule
          (called multiline import rule), the regex ``REGEX_IMPORT_RULE``
          return a list of unquoted items for each rule.
  
          Args:
              declarations (list): A SCSS source.
  
          Returns:
              list: Given SCSS source with all comments removed.