title: Keycloak map multiple user attributes
body: <p>I've followed the guide at [1] to map a single user attribute. However, I need to map all attributes to an array, so that every attribute for a particular User shows up in an attribute array of the access token (Or better, restrict attributes to a certain group of attributes, but I guess user attributes are only a flat key/value map). </p>
  
  <p>I tried out setting a wildcard * in the User Attribute field of the client mapper. But no matter what I do, I can ony set one attribute at a time given an actual attribute key of  a user's attribute map.</p>
  
  <p>[1] <a href="https://stackoverflow.com/questions/32678883/keycloak-retrieve-custom-attributes-to-keycloakprincipal">Keycloak retrieve custom attributes to KeycloakPrincipal</a></p>