command.php

<?php

class Example
{
  protected $command = array(
    'select' => 'Orient\Query\...\...\Select',
    ...
    ...
  );

  public function __construct(array $commands)
  {
    $this->commands = array_merge($this->commands, $commands);
  }

  public function delete($from)
  {
    $class = $this->getCommandClass($from)
    $this->command = new $class($from);
  }
}