code: public boolean has (String key) {
          String[] path = Key.split (key);
          int index = binarySearch (path[0]);
          try {
              return (index >= 0) &&
                      ((path.length == 1) ||
                              ((BagObject) container[index].value).has (path[1]));
          } catch (ClassCastException classCastException) {
              // if a requested value is not a BagObject - this should be an exceptional case
              return false;
          }
      }
docs: Return whether or not the requested key or path is present in the BagObject or hierarchical
  "bag-of-bags"
  
  @param key A string value used to index the element, using "/" as separators, for example:
  "com/brettonw/bag/key".
  @return A boolean value, true if the key is present in the underlying store. Note that null
  values are not stored (design decision), so this equivalent to checking for null.