if ( phreakNode == PhreakJoinNode.class ) {
new PhreakJoinNode().doNode( (JoinNode) betaNode, sinkNode,
bm, wm, leftTuples, actualResultLeftTuples, previousResultTuples );
} else if ( phreakNode == PhreakNotNode.class ) {
new PhreakNotNode().doNode( (NotNode) betaNode, sinkNode,
bm, wm, leftTuples, actualResultLeftTuples, previousResultTuples );
} else if ( phreakNode == PhreakExistsNode.class ) {
new PhreakExistsNode().doNode( (ExistsNode) betaNode, sinkNode,
bm, wm, leftTuples, actualResultLeftTuples, previousResultTuples );
}