code: def validate(self, lsid, check_existing=True):
          
          # Base LSID matches
          if not lsid.startswith(self.base_lsid):
              return False
  
          # Module number isn't already taken
          if check_existing and lsid in self.registered_modules:
              return False
  
          # Everything checks out, return True
          return True
docs: Validates an LSID with the LSID authority.
          :param lsid:
          :return: boolean - is the LSID valid with this authority?