TXNetFile

 Create a TXNetFile object. A TXNetFile object is the same as a TNetFile
 (from which the former derives) except that the protocol is extended to
 support dealing with new xrootd data server or xrootd load balancer
 server.

 The "url" argument must be of the form

   root://server1:port1[,server2:port2,...,serverN:portN]/pathfile,

 Note that this means that multiple servers (>= 1) can be specified in
 the url. The connection will try to connect to the first server:port
 and if that does not succeed, it will try the second one, and so on
 until it finds a server that will respond.

 See the TNetFile documentation for the description of the other arguments.

 The creation consists of internal variable settings (most important is
 the client's domain), creation of a TXUrl array containing all specified
 urls (a single url is serverX:portX/pathfile), trying to connect to the
 servers calling Connect() method, getting a valid access to the remote
 server the client is connected to using GetAccessToSrv() method,
 recognizing the remote server (if an old rootd the TNetFile's Create
 method will be called).

 The options field of the URL can be used for the following purposes:
   a. open a non-ROOT generic file
      "root://server1:port1[,server2:port2,...]/pathfile?filetype=raw"
   b. re-check the environment variables
      "root://server1:port1[,server2:port2,...]/pathfile?checkenv"

 Destructor.

 Form url for rootd socket.

 The real creation work is done here.

 Find out the remote rootd protocol version.
 Returns -1 in case of error.

 The real creation work is done here.

 Override TNetFile::ReadBuffer to deal with the xrootd server.
 Returns kTRUE in case of errors.

 Read the nbuf blocks described in arrays pos and len,
 where pos[i] is the seek position of block i of length len[i].
 Note that for nbuf=1, this call is equivalent to TFile::ReafBuffer
 This function is overloaded by TNetFile, TWebFile, etc.
 Returns kTRUE in case of failure.
 Note: This is the overloading made in TXNetFile, If ReadBuffers
 is supported by xrootd it will try to gt the whole list from one single
 call avoiding the latency of multiple calls

 Override TNetFile::WriteBuffer to deal with the xrootd server.
 Returns kTRUE in case of errors.

 Initialize the file. Makes sure that the file is really open before
 calling TFile::Init. It may block.

 Return kTRUE if the file is open, kFALSE otherwise.

 Return status of asynchronous request

 Re-open the file (see TNetFile::ReOpen() or TFile::ReOpen()
 for more details).

 Close the file (see TNetFile::Close() or TFile::Close()
 for more details).

 Flushes un-written data.

 Override TNetFile::SysStat (see parent's method for more details).

 Override TNetFile::SysClose (see parent's method for more details).

 Override TNetFile::SysOpen (see parent's method for more details).

 Return file size.

 Set the relevant environment variables