code: private function parseEnumValueDefinition()
      {
          $start       = $this->lexer->token;
          $description = $this->parseDescription();
          $name        = $this->parseName();
          $directives  = $this->parseDirectives(true);
  
          return new EnumValueDefinitionNode([
              'name'        => $name,
              'directives'  => $directives,
              'loc'         => $this->loc($start),
              'description' => $description,
          ]);
      }
docs: @return EnumValueDefinitionNode
  
  @throws SyntaxError