protected function validateDuplicates()
	{
		return ( !$this->duplicatesExistForColumn( $this->model->getQualifiedLeftColumnName() ) && !$this->duplicatesExistForColumn( $this->model->getQualifiedRightColumnName() ) );
	}
protected function validateDuplicates()
	{
		return ( !$this->duplicatesExistForColumn( $this->model->getQualifiedLeftColumnName() ) && !$this->duplicatesExistForColumn( $this->model->getQualifiedRightColumnName() ) );
	}
protected function validateDuplicates ( ) { return ( ! $ this -> duplicatesExistForColumn ( $ this -> model -> getQualifiedLeftColumnName ( ) ) && ! $ this -> duplicatesExistForColumn ( $ this -> model -> getQualifiedRightColumnName ( ) ) ) ; }
Checks that there are no duplicates for the `lft` and `rgt` columns.

@return boolean
Checks that there are no duplicates for the lft and rgt columns .