code: public Set<GrantedAuthority> convertGroupsToGrantedAuthorities(final List<UserGroup> groups) {
          // Map the authority information to one or more GrantedAuthority's and add it to mappedAuthorities
          final Set<GrantedAuthority> mappedAuthorities = groups.stream().filter(this::isValidUserGroupToGrantAuthority)
                  .map(userGroup -> new SimpleGrantedAuthority(DEFAULT_ROLE_PREFIX + userGroup.getDisplayName()))
                  .collect(Collectors.toCollection(LinkedHashSet::new));
          if (mappedAuthorities.isEmpty()) {
              mappedAuthorities.add(DEFAULT_AUTHORITY);
          }
  
          return mappedAuthorities;
      }
docs: Converts UserGroup list to Set of GrantedAutorities
  @param groups
  @return