countermand vs have change of heart

countermand

noun
  • An order to the contrary of a previous one. 

verb
  • To recall a person or unit with such an order. 

  • To counteract, to act against, to frustrate. 

  • To revoke (a former command); to cancel or rescind by giving an order contrary to one previously given. 

  • To cancel an order for (some specified goods). 

have change of heart

How often have the words countermand and have change of heart occurred in a corpus of books? (source: Google Ngram Viewer )