code: @Override
      public String put(String key, String value) {
  
          String result = remove(key);
          add(key, value, false);
          return result;
      }
docs: Set a parameter for this configuration.<p>
  
  If the parameter already exists then the existing value will be replaced.<p>
  
  @param key the parameter to set
  @param value the value to set
  
  @return the previous String value from the parameter map