code: func NewhttpClientMock(valid bool) *HTTPClientMock {
  
  	return &HTTPClientMock{
  		apiKeyPublic:  "apiKeyPublic",
  		apiKeyPrivate: "apiKeyPrivate",
  		client:        http.DefaultClient,
  		validCreds:    valid,
  		fx:            fixtures.New(),
  		CallFunc: func() (int, int, error) {
  			if valid == true {
  				return 1, 1, nil
  			}
  			return 0, 0, errors.New("Unexpected error: Unexpected server response code: 401: EOF")
  		},
  		SendMailV31Func: func(req *http.Request) (*http.Response, error) {
  			return nil, nil
  		},
  	}
  }
docs: // NewhttpClientMock instanciate new httpClientMock