ho wto use wait in appium code example

Example 1: how to add wait in appium

WebDriverWait wait = new WebDriverWait(driver, 30);
wait.until(ExpectedConditions.elementToBeClickable(By
        .xpath("//android.widget.Button[contains(@text, 'Log In')]")));

Example 2: how to add wait in appium

WebDriverWait wait = new WebDriverWait(driver, 30);
wait.until(ExpectedConditions.presenceOfElementLocated(By
            .xpath("//android.widget.TextView[contains(@resource-id, 'action_bar_title')]")));