code: public void setHeaders(AmqpArguments headers) {
          if (headers == null) {
              _properties.remove(AMQP_PROP_HEADERS);
              return;
          }
          
          _properties.put(AMQP_PROP_HEADERS, headers);
      }
docs: Sets the value of "headers" property.  If a null value is passed
  in, it indicates that the property is not set.
  
  @param  headers    value of "headers" property