Adding claims to a JWT on Spring Boot

JWTAuthenticationFilter.java

package com.auth0.samples.authapi.security;

// ... imports

public class JWTAuthenticationFilter extends UsernamePasswordAuthenticationFilter {
	// ...

	@Override
	protected void successfulAuthentication(HttpServletRequest req,
											HttpServletResponse res,
											FilterChain chain,
											Authentication auth) throws IOException, ServletException {

		String token = Jwts.builder()
				.setSubject(((User) auth.getPrincipal()).getUsername())
				.claim("preference", "dogs") // <========================================= HERE
				.setExpiration(new Date(System.currentTimeMillis() + EXPIRATION_TIME))
				.signWith(SignatureAlgorithm.HS512, SECRET)
				.compact();
		res.addHeader(HEADER_STRING, TOKEN_PREFIX + " " + token);
	}
}

should I place new claim in JWTAuthentication or JWTAuthorization?