code: def size(self, fileToCheck, connId='default'):
          
          thisConn = self.__getConnection(connId)
          outputMsg = ""
          try:
              tmpSize = thisConn.size(fileToCheck)
              outputMsg += str(tmpSize)
          except ftplib.all_errors as e:
              raise FtpLibraryError(str(e))
          if self.printOutput:
              logger.info(outputMsg)
          return outputMsg
docs: Checks size of a file on FTP server. Returns size of a file in bytes (integer).
          Parameters:
          - fileToCheck - file name or path to a file on FTP server
          - connId(optional) - connection identifier. By default equals 'default'
          Example:
          | ${file1size} = | size | /home/myname/tmp/uu.txt | connId=ftp1 |
          | Should Be Equal As Numbers | ${file1size} | 31 |  |
  
          Note that the SIZE command is not standardized, but is supported by many
           common server implementations.