@Override
public Object visit(ASTGraphGraphPattern node, Object data)
throws VisitorException
{
Var oldContext = graphPattern.getContextVar();
Scope oldScope = graphPattern.getStatementPatternScope();
ValueExpr newContext = (ValueExpr)node.jjtGetChild(0).jjtAccept(this, null);
graphPattern.setContextVar(valueExpr2Var(newContext));
graphPattern.setStatementPatternScope(Scope.NAMED_CONTEXTS);