code: public function setEntityPrototype($entityPrototype)
      {
          if (!is_object($entityPrototype)) {
              throw new Exception\InvalidArgumentException(
                  sprintf(
                      '%s expects parameter 1 to be an object, %s provided instead',
                      __METHOD__,
                      is_object($entityPrototype) ? get_class($entityPrototype) : gettype($entityPrototype)
                  )
              );
          }
          $this->entityPrototype = $entityPrototype;
  
          return $this;
      }
docs: Sets entity prototype of namespace entity
  
  @param  object $entityPrototype
  @return self