Sokil\Mongo\Document\InvalidDocumentException::setDocument PHP Method

    public function setDocument(Structure $document)
    {
        $this->document = $document;
        return $this;
    }

 /**
  *
  * @throws \Sokil\Mongo\Document\InvalidDocumentException
  * @return \Sokil\Mongo\Document
  */
 public function validate()
 {
     if ($this->triggerEvent('beforeValidate')->isCancelled()) {
         return $this;
     }
     if (!$this->isValid()) {
         $exception = new InvalidDocumentException('Document not valid');
         $exception->setDocument($this);
         $this->triggerEvent('validateError');
         throw $exception;
     }
     $this->triggerEvent('afterValidate');
     return $this;
 }