public function supplier( $supIds, $listtype = 'default' )
	{
		if( !empty( $supIds ) && ( $ids = array_unique( $this->validateIds( (array) $supIds ) ) ) !== [] )
		{
			$func = $this->filter->createFunction( 'index.supplier:position', [$listtype, $ids] );

			$this->conditions[] = $this->filter->compare( '==', 'index.supplier.id', $ids );
			$this->conditions[] = $this->filter->compare( '>=', $func, 0 );

			$func = $this->filter->createFunction( 'sort:index.supplier:position', [$listtype, $ids] );
			$this->sort = $this->filter->sort( '+', $func );
		}

		return $this;
	}