code: public static SimpleAttributeDefinitionBuilder create(final String name, final ModelNode node) {
          ModelType type = node.get(ModelDescriptionConstants.TYPE).asType();
          boolean nillable = node.get(ModelDescriptionConstants.NILLABLE).asBoolean(true);
          boolean expressionAllowed = node.get(ModelDescriptionConstants.EXPRESSIONS_ALLOWED).asBoolean(false);
          ModelNode defaultValue = nillable ? node.get(ModelDescriptionConstants.DEFAULT) : new ModelNode();
          return SimpleAttributeDefinitionBuilder.create(name, type, nillable)
                  .setDefaultValue(defaultValue)
                  .setAllowExpression(expressionAllowed);
      }
docs: /*
  "code" => {
  "type" => STRING,
  "description" => "Fully Qualified Name of the Security Vault Implementation.",
  "expressions-allowed" => false,
  "nillable" => true,
  "min-length" => 1L,
  "max-length" => 2147483647L,
  "access-type" => "read-write",
  "storage" => "configuration",
  "restart-required" => "no-services"
  },