code: public function parseSchema($openApiSpec)
      {
          $openApiSpecContents = file_get_contents($openApiSpec);
          $schemaClass         = self::OPEN_API_MODEL;
          $schema              = null;
          $jsonException       = null;
          $yamlException       = null;
  
          try {
              return $this->serializer->deserialize(
                  $openApiSpecContents,
                  $schemaClass,
                  self::CONTENT_TYPE_JSON,
                  [
                      'document-origin' => $openApiSpec
                  ]
              );
          } catch (\Exception $exception) {
              $jsonException = $exception;
          }
  
          $content = Yaml::parse($openApiSpecContents, Yaml::PARSE_OBJECT | Yaml::PARSE_OBJECT_FOR_MAP | Yaml::PARSE_DATETIME | Yaml::PARSE_EXCEPTION_ON_INVALID_TYPE);
          $openApiSpecContents = json_encode($content);
  
          return $this->serializer->deserialize(
              $openApiSpecContents,
              $schemaClass,
              self::CONTENT_TYPE_JSON,
              [
                  'document-origin' => $openApiSpec
              ]
          );
      }
docs: Parse an file into a OpenAPI Schema model
  
  @param string $openApiSpec
  
  @return OpenApi
  
  @throws ParseFailureException