docs: def get_magic_comment(self, name, expand_macros=False):
          """Return a value of # name=value comment in spec or None."""
          match = re.search(r'^#\s*?%s\s?=\s?(\S+)' % re.escape(name),
                            self.txt, flags=re.M)
          if not match:
              return None
  
          val = match.group(1)
          if expand_macros and has_macros(val):
              # don't parse using rpm unless required
              val = self.expand_macro(val)
          return val