code: public String getMessage()
      {
          String base = super.getMessage();
  
          if( null == base )
          {
              return "Failed to access " + m_variable + " environment variable";
          }
  
          return "Failed to access " + m_variable + " environment variable - " + base;
      }
docs: Prepends variable name to the base message.
  
  @return the message of the Exception.
  
  @see java.lang.Throwable#getMessage()