code: public void setOption(String optName, String optValue) {
          if (optValue == null) {
              m_optionMap.remove(optName);
          } else {
              m_optionMap.put(optName, optValue.trim());
          }
      }
docs: Set the option with the given name to the given value. If the option value is null,
  the option is "unset". If the option has an existing value, it is replaced.
  
  @param optName   Name of option to set (case-sensitive).
  @param optValue  New value of option or null to "unset".