parameters: (self, old_sth, new_sth)
return_statement: return proof
docstring: Verifies that old STH is consistent with new STH.
  
          Returns: Deferred that fires with boolean indicating whether updating
          succeeded.
  
          Deferred raises: error.ConsistencyError if STHs were inconsistent
docstring_summary: Verifies that old STH is consistent with new STH.
docstring_tokens: Verifies that old STH is consistent with new STH .
function: def _verify_consistency(self, old_sth, new_sth):
          """Verifies that old STH is consistent with new STH.
  
          Returns: Deferred that fires with boolean indicating whether updating
          succeeded.
  
          Deferred raises: error.ConsistencyError if STHs were inconsistent"""
          proof = self.__client.get_sth_consistency(old_sth.tree_size,
                                                    new_sth.tree_size)
          proof.addCallback(self.__verify_consistency_callback, old_sth, new_sth)
          return proof
function_tokens: def _verify_consistency ( self , old_sth , new_sth ) : proof = self . __client . get_sth_consistency ( old_sth . tree_size , new_sth . tree_size ) proof . addCallback ( self . __verify_consistency_callback , old_sth , new_sth ) return proof