code: def find_element(self, by=By.ID, value=None):
          
          if self._w3c:
              if by == By.ID:
                  by = By.CSS_SELECTOR
                  value = '[id="%s"]' % value
              elif by == By.TAG_NAME:
                  by = By.CSS_SELECTOR
              elif by == By.CLASS_NAME:
                  by = By.CSS_SELECTOR
                  value = ".%s" % value
              elif by == By.NAME:
                  by = By.CSS_SELECTOR
                  value = '[name="%s"]' % value
  
          return self._execute(Command.FIND_CHILD_ELEMENT,
                               {"using": by, "value": value})['value']
docs: Find an element given a By strategy and locator. Prefer the find_element_by_* methods when
          possible.
  
          :Usage:
              ::
  
                  element = element.find_element(By.ID, 'foo')
  
          :rtype: WebElement