code: def get_namespace_preorder( self, namespace_id_hash ):
          
          namespace_preorder = namedb_get_namespace_preorder( self.db, namespace_id_hash, self.lastblock ) 
          return namespace_preorder
docs: Given the hash(namesapce_id, sender_script_pubkey, reveal_addr) for a 
          namespace that is being imported, get its associated NAMESPACE_PREORDER
          record.
  
          Return the namespace preorder record on success.
          Return None if not found, if the namespace is currently not preordered, or if the preorder record is expired.