function constructTree1() {
  var queryContext = new lf.query.SelectContext(hr.db.getSchema());
  queryContext.from = [e];
  queryContext.where = lf.op.and(e.id.gt('100'), e.salary.eq(10000));

  var selectNode1 = createSelectStep(queryContext, 0);
  var selectNode2 = createSelectStep(queryContext, 1);
  selectNode1.addChild(selectNode2);
  var tableAccessNode = new lf.proc.TableAccessFullStep(
      hr.db.getGlobal(), queryContext.from[0]);
  selectNode2.addChild(tableAccessNode);
  return {
    queryContext: queryContext,
    root: selectNode1
  };
}
Constructs a tree where:
 - One TableAccessFullStep node exists.
 - Multiple SelectStep nodes exist without any nodes in-between them.
@return {lf.testing.treeutil.Tree} The constructed tree and corresponding
    query context.