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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def is_present(self, locator, search_object=None):
 """ Determines whether an element is present on the page, retrying once if unable to locate @type locator: webdriverwrapper.support.locator.Locator @param locator: the locator or css string used to query the element @type search_object: webdriverwrapper.WebElementWrapper @param search_object: Optional WebElement to start search with. If null, search will be on self.driver """

        all_elements = self._find_immediately(locator, search_object=search_object)

        if all_elements is not None and len(all_elements) > 0:
            return True
        else:
            return False