title: Keycloak create a custom identity provider mapper
body: <p>i have an open id provider and i use this provider as identity broker of keycloak. I want to map roles (claims) which sent from broker to keycloak (and keycloak will sent mapped roles in its jwt). I want to know how to implement and add a custom mapper to keycloak (like hardcodedmapper, attributemapper in keycloak). Can i do this? Thanks</p>