code: public EntityRole getClosedListEntityRole(UUID appId, String versionId, UUID entityId, UUID roleId) {
          return getClosedListEntityRoleWithServiceResponseAsync(appId, versionId, entityId, roleId).toBlocking().single().body();
      }
docs: Get one entity role for a given entity.
  
  @param appId The application ID.
  @param versionId The version ID.
  @param entityId entity ID.
  @param roleId entity role ID.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @throws ErrorResponseException thrown if the request is rejected by server
  @throws RuntimeException all other wrapped checked exceptions if the request fails to be sent
  @return the EntityRole object if successful.