code: def push(self, url, title=''):
          
          # ignore refreshes of the top level
          if self.currentUrl() == url or self._blockStack:
              return False
          
          self._blockStack = True
          
          self._stack = self._stack[:self._index+1]
          self._stack.append((nativestring(url), nativestring(title)))
          
          over = len(self._stack) - self.maximum()
          if over > 0:
              self._stack = self._stack[over:]
          
          self._index = len(self._stack) - 1
          
          self.canGoBackChanged.emit(self.canGoBack())
          self.canGoForwardChanged.emit(self.canGoForward())
          
          self._blockStack = False
          return True
docs: Pushes the url into the history stack at the current index.
          
          :param      url | <str>
          
          :return     <bool> | changed