/src/main/java/org/htmlunit/html/HtmlElement.java
if ( required ) { setAttribute ( ATTRIBUTE_REQUIRED, ATTRIBUTE_REQUIRED ) ; }
} public boolean isOptional() { return isRequiredSupported() && !hasAttribute(ATTRIBUTE_REQUIRED); } public void setRequired(final boolean required) { if (isRequiredSupported()) { <extra_id_0> else { removeAttribute(ATTRIBUTE_REQUIRED); } } } @Override