Sokil\Mongo\Structure::unsetField PHP Method

    public function unsetField($selector)
    {
        // modify
        $arraySelector = explode('.', $selector);
        $chunksNum = count($arraySelector);
        // optimize one-level selector search
        if (1 == $chunksNum) {
            // check if field exists
            if (isset($this->data[$selector])) {
                // unset field
                unset($this->data[$selector]);
                // mark field as modified
                $this->modifiedFields[] = $selector;
            }
            return $this;
        }
        // find section
        $section =& $this->data;
        for ($i = 0; $i < $chunksNum - 1; $i++) {
            $field = $arraySelector[$i];
            if (!isset($section[$field])) {
                return $this;
            }
            $section =& $section[$field];
        }
        // check if field exists
        if (isset($section[$arraySelector[$chunksNum - 1]])) {
            // unset field
            unset($section[$arraySelector[$chunksNum - 1]]);
            // mark field as modified
            $this->modifiedFields[] = $selector;
        }
        return $this;
    }

 /**
  * Remove field
  * 
  * @param string $fieldName field name
  * @return \Sokil\Mongo\Document
  */
 public function unsetField($fieldName)
 {
     if (!$this->has($fieldName)) {
         return $this;
     }
     parent::unsetField($fieldName);
     if ($this->getId()) {
         $this->operator->unsetField($fieldName);
     }
     return $this;
 }