src/GraphBuilder.php
public function union( $graphs /* graphs ... */ ) {
		$graphs = is_array( $graphs ) ? $graphs : func_get_args();

		$this->unions[] = implode( ' UNION', array_map( function( GraphBuilder $graph ) {
			return ' {' . $graph->getSPARQL() . ' }';
		}, $graphs ) );

		return $this;
	}
public function union( $graphs /* graphs ... */ ) {
		$graphs = is_array( $graphs ) ? $graphs : func_get_args();

		$this->unions[] = implode( ' UNION', array_map( function( GraphBuilder $graph ) {
			return ' {' . $graph->getSPARQL() . ' }';
		}, $graphs ) );

		return $this;
	}
public function union ( $ graphs /* graphs ... */ ) { $ graphs = is_array ( $ graphs ) ? $ graphs : func_get_args ( ) ; $ this -> unions [ ] = implode ( ' UNION' , array_map ( function ( GraphBuilder $ graph ) { return ' {' . $ graph -> getSPARQL ( ) . ' }' ; } , $ graphs ) ) ; return $ this ; }
Adds the given graphs as alternative conditions.

@param GraphBuilder|GraphBuilder[] $graphs
@return self
@throws InvalidArgumentException
Adds the given graphs as alternative conditions .