Method deepCopy

fe/src/main/java/org/apache/impala/analysis/Expr.java:1293–1308

Create a deep copy of 'ls'. The elements of the returned list are of the same type as the input list.

(List<List<C>> ls)

   * type as the input list.
   */
  public static <C extends Expr> List<List<C>> deepCopy(List<List<C>> ls) {
    Preconditions.checkNotNull(ls);
    List<List<C>> result = new ArrayList<>(ls.size());
    for (List<C> l : ls) {
      if (l == null) {
        result.add(null);
        continue;
      }
      List<C> l2 = new ArrayList<>(l.size());
      for (Expr element : l) {
        l2.add((C) element.clone());
      }
      result.add(l2);
    }
    return result;
  }

  /**
   * Create a clone of the expression including analysis state with a different