global $woocommerce;
if ( isset( $woocommerce->session ) )
$woocommerce->session->'name' = 'value';
global $woocommerce;
if ( isset( $woocommerce->session ) && isset( $woocommerce->session->'name' ) )
$name_velue = $woocommerce->session->'name';
global $woocommerce;
if ( isset( $woocommerce->session ) )
unset( $woocommerce->session->'name' );