code: public function build()
      {
          $this->validate();
  
          if (is_array($this->inputs) && count($this->inputs) == 1) {
              $this->inputs = $this->inputs[0];
          }
  
          return new Command\MapReduce\Fetch($this);
      }
docs: {@inheritdoc}
  
  @return Command\MapReduce\Fetch;