public function get_model( $pk ) {

		$i = $this->get_model_index( $pk );

		if ( $i === - 1 ) {
			return null;
		}

		return $this->elements[ $i ];
	}
public function get_model( $pk ) {

		$i = $this->get_model_index( $pk );

		if ( $i === - 1 ) {
			return null;
		}

		return $this->elements[ $i ];
	}
public function get_model ( $ pk ) { $ i = $ this -> get_model_index ( $ pk ) ; if ( $ i === - 1 ) { return null ; } return $ this -> elements [ $ i ] ; }
Retrieve a model by its primary key.

@since 2.0

@param string|int $pk

@return Model|mixed|null
Retrieve a model by its primary key .