code: public OpenAPI read()
      {
      JsonNode json;
      
      try
        {
        ObjectMapper mapper =
          isYaml()
          ? ObjectMapperFactory.createYaml()
          : ObjectMapperFactory.createJson();
      
        json = mapper.readTree( getReader());
        }
      catch( Exception e)
        {
        throw new OpenApiReaderException( getLocation(), e);
        }
  
      SwaggerParseResult parseResult= new OpenAPIDeserializer().deserialize( json, Objects.toString( getLocation(), null));
  
      Optional.of( parseResult)
        .map( SwaggerParseResult::getMessages)
        .filter( messages -> !messages.isEmpty())
        .map( messages -> new OpenApiReaderException( getLocation(), messages))
        .ifPresent( failure -> { throw failure; });
  
      return parseResult.getOpenAPI();
      }
docs: Returns the {@link OpenAPI} instance represented by this document.