code: protected AspImpl getAspForNullRc() {
          // We know if null RC, ASP cannot be shared and AspFactory will
          // have only one ASP
  
          AspImpl aspImpl = (AspImpl) this.aspFactoryImpl.aspList.get(0);
  
          if (this.aspFactoryImpl.aspList.size() > 1) {
              // verify that AS to which this ASP is added is also having null
              // RC or this asp is not shared by any other AS in which case we
              // know messages are intended for same AS
  
              ErrorCode errorCodeObj = this.aspFactoryImpl.parameterFactory.createErrorCode(ErrorCode.Invalid_Routing_Context);
              sendError(null, errorCodeObj);
              return null;
          }
  
          return aspImpl;
      }
docs: Get's the ASP for any ASP Traffic Maintenance, Management, Signalling Network Management and Transfer m3ua message's
  received which has null Routing Context
  
  @return