System.Text.RegularExpressions.RegexNode.ChildCount C# (CSharp) Method

        internal int ChildCount()
        {
            return _children == null ? 0 : _children.Count;
        }

 internal RegexReplacement(string rep, RegexNode concat, System.Collections.Generic.Dictionary<object,object> _caps)
 {
     this._rep = rep;
     if (concat.Type() != 0x19)
     {
         throw new ArgumentException(RegExRes.GetString(0x25));
     }
     StringBuilder builder = new StringBuilder();
     ArrayList list = new ArrayList();
     ArrayList list2 = new ArrayList();
     for (int i = 0; i < concat.ChildCount(); i++)
     {
         RegexNode node = concat.Child(i);
         switch (node.Type())
         {
             case 9:
             {
                 builder.Append(node._ch);
                 continue;
             }
             case 12:
             {
                 builder.Append(node._str);
                 continue;
             }
             case 13:
             {
                 if (builder.Length > 0)
                 {
                     list2.Add(list.Count);
                     list.Add(builder.ToString());
                     builder.Length = 0;
                 }
                 int num = node._m;
                 if ((_caps != null) && (num >= 0))
                 {
                     num = (int) _caps[num];
                 }
                 list2.Add(-5 - num);
                 continue;
             }
         }
         throw new ArgumentException(RegExRes.GetString(0x25));
     }
     if (builder.Length > 0)
     {
         list2.Add(list.Count);
         list.Add(builder.ToString());
     }
     this._strings = new string[list.Count];
     list.CopyTo(0, this._strings, 0, list.Count);
     this._rules = new int[list2.Count];
     for (int j = 0; j < list2.Count; j++)
     {
         this._rules[j] = (int) list2[j];
     }
 }