Element (Namespace namespace) { if (namespace == null) { namespace = Namespace.NO_NAMESPACE; } if (additionalNamespaces != null) { String reason = Verifier.checkNamespaceCollision(namespace, additionalNamespaces); if (reason != null) { throw new IllegalAddException(this, namespace, reason); } } if (hasAttributes()) { for (Attribute a : getAttributes()) { final String reason = Verifier.checkNamespaceCollision(namespace, a); if (reason != null) { throw new IllegalAddException(this, namespace, reason); } } } this.namespace = namespace; return this; }