code: @Post("/metadata/{projectName}/repos/{repoName}/perm/users")
      public CompletableFuture<Revision> addSpecificUserPermission(
              @Param("projectName") String projectName,
              @Param("repoName") String repoName,
              IdentifierWithPermissions memberWithPermissions,
              Author author) {
          final User member = new User(loginNameNormalizer.apply(memberWithPermissions.id()));
          return mds.addPerUserPermission(author, projectName, repoName,
                                          member, memberWithPermissions.permissions());
      }
docs: POST /metadata/{projectName}/repos/{repoName}/perm/users
  
  <p>Adds {@link Permission}s of the specific users to the specified {@code repoName} in the
  specified {@code projectName}.