Cannot click the checkbox in Selenium

I am trying to click on the checkbox that is displayed for "I am not a robot" verification. I am getting the error "Given xpath expression "//span[contains[@class, '.recaptcha-checkbox-checkmark']" is invalid: SyntaxError: The expression is not a legal expression."

The details are given below

<span class="recaptcha-checkbox goog-inline-block recaptcha-checkbox-unchecked rc-anchor-checkbox" role="checkbox" aria-checked="false" id="recaptcha-anchor" tabindex="0" dir="ltr" aria-labelledby="recaptcha-anchor-label">
  <div class="recaptcha-checkbox-border" role="presentation"></div>
  <div class="recaptcha-checkbox-borderAnimation" role="presentation"</div>
<div class="recaptcha-checkbox-spinner" role="presentation"></div>
<div class="recaptcha-checkbox-spinnerAnimation" role="presentation"></div>
<div class="recaptcha-checkbox-checkmark" role="presentation"></div>
    </span>

What I tried:

public void I_mark_checkbox_for_human_verification() throws Throwable   
{       
   WebDriverWait wait = new WebDriverWait(driver, 10);
   WebElement element = wait.until(ExpectedConditions.visibilityOfElementLocated(By.xpath("//span[contains[@class, 'recaptcha-checkbox goog-inline-block recaptcha-checkbox-unchecked rc-anchor-checkbox']")));

    element.click();
}

Please help me to resolve this. Any help is appreciated.