import com.hp.hpl.jena.sparql.algebra.op.OpExt; //导入依赖的package包/类
private Op substitute(OpExt op) {
	try {
		return op.apply(this);
	} catch (Exception e) {
		// May happen if the OpExt doesn't implement apply()
		return op;
	}
}
 

import com.hp.hpl.jena.sparql.algebra.op.OpExt; //导入依赖的package包/类
@Override
   protected void visitExt(OpExt op) {
op.visit(visitor);
   }
 

import com.hp.hpl.jena.sparql.algebra.op.OpExt; //导入依赖的package包/类
@Override
protected void visitExt(OpExt op)
{
	op.visit(visitor) ;
}
 

import com.hp.hpl.jena.sparql.algebra.op.OpExt; //导入依赖的package包/类
public void visit(OpExt opExt) {
	wrapInCurrentFilter(opExt);
}
 

import com.hp.hpl.jena.sparql.algebra.op.OpExt; //导入依赖的package包/类
@Override
public Op transform(OpExt opExt) {
	return substitute(opExt);
}