public static List<String> getColumnNamesFromSortCols(List<Order> sortCols) {
    if(sortCols == null) {
      return Collections.emptyList();
    }
    List<String> names = new ArrayList<String>();
    for (Order o : sortCols) {
      names.add(o.getCol());
    }
    return names;
  }
Remove elements from the classpath, if possible. This will only work if the current thread context class loader is
an UDFClassLoader (i.e. if we have created it).

@param pathsToRemove
         Array of classpath elements
ql/src/java/org/apache/hadoop/hive/ql/exec/Utilities.java