code: private List<SimpleJsonSchema> mergeRepositories(List<JsonSchemaRepository> schemaRepositories) {
          return schemaRepositories.stream()
                  .map(JsonSchemaRepository::getSchemas)
                  .flatMap(List::stream)
                  .collect(Collectors.toList());
      }
docs: Merges the list of given schema repositories to one unified list of json schemas
  @param schemaRepositories The list of json schemas to merge
  @return A list of all json schemas contained in the repositories