public static String getExprListString(Collection<?  extends ExprNodeDesc> exprs, boolean userLevelExplain) {
    return getExprListString(exprs, userLevelExplain, false);
  }
Remove prefix from "Path -&gt; Alias"
This is required for testing.
In order to verify that path is right, we need to display it in expected test result.
But, mask pattern masks path with some patterns.
So, we need to remove prefix from path which triggers mask pattern.
@param origiKey
@return
ql/src/java/org/apache/hadoop/hive/ql/plan/PlanUtils.java