code: public SafeHtmlBuilder setSrc(SafeUrl value) {
      if (!SRC_SAFE_URL_ELEMENT_WHITELIST.contains(elementName)) {
        throw new IllegalArgumentException(
            "Attribute \"src\" with a SafeUrl value can only be used "
                + "by one of the following elements: "
                + SRC_SAFE_URL_ELEMENT_WHITELIST);
      }
      return setAttribute("src", value.getSafeUrlString());
    }
docs: Sets the {@code src} attribute for this element.
  
  <p>The attribute {@code src} with a {@code SafeUrl} value is allowed on these elements:
  
  <ul>
  <li>{@code audio}
  <li>{@code img}
  <li>{@code input}
  <li>{@code source}
  <li>{@code video}
  </ul>
  
  @throws IllegalArgumentException if the {@code src} attribute with a {@code SafeUrl} value is
  not allowed on this element