class TSelector: public TObject

 Default selector ctor.

 Selector destructor.

 Abort processing. If what = kAbortProcess, the Process() loop will be
 aborted. If what = kAbortFile, the current file in a chain will be
 aborted and the processing will continue with the next file, if there
 is no next file then Process() will be aborted. Abort() can also  be
 called from Begin(), SlaveBegin(), Init() and Notify(). After abort
 the SlaveTerminate() and Terminate() are always called. The abort flag
 can be checked in these methods using GetAbort().

 The code in filename is loaded (interpreted or compiled, see below),
 filename must contain a valid class implementation derived from TSelector.

 If filename is of the form file.C, the file will be interpreted.
 If filename is of the form file.C++, the file file.C will be compiled
 and dynamically loaded. The corresponding binary file and shared
 library will be deleted at the end of the function.
 If filename is of the form file.C+, the file file.C will be compiled
 and dynamically loaded. At next call, if file.C is older than file.o
 and file.so, the file.C is not compiled, only file.so is loaded.

 The static function returns a pointer to a TSelector object

 Find out if this is a standard selection used for Draw actions
 (either TSelectorDraw, TProofDraw or deriving from them).

    This method is called before processing entry. It is the user's responsability to read
    the corresponding entry in memory (may be just a partial read).
    The function returns kTRUE if the entry must be processed,
    kFALSE otherwise. This method is obsolete, use Process().

 WARNING when a selector is used with a TChain:
    in the Process, ProcessCut, ProcessFill function, you must use
    the pointer to the current Tree to call GetEntry(entry).
    entry is always the local entry number in the current tree.
    Assuming that fChain is the pointer to the TChain being processed,
    use fChain->GetTree()->GetEntry(entry);

 This method is called for all selected entries. User fills histograms
 in this function.  This method is obsolete, use Process().

 WARNING when a selector is used with a TChain:
    in the Process, ProcessCut, ProcessFill function, you must use
    the pointer to the current Tree to call GetEntry(entry).
    entry is always the local entry number in the current tree.
    Assuming that fChain is the pointer to the TChain being processed,
    use fChain->GetTree()->GetEntry(entry);

 The Process() function is called for each entry in the tree (or possibly
 keyed object in the case of PROOF) to be processed. The entry argument
 specifies which entry in the currently loaded tree is to be processed.
 It can be passed to either t01::GetEntry() or TBranch::GetEntry()
 to read either all or the required parts of the data. When processing
 keyed objects with PROOF, the object is already loaded and is available
 via the fObject pointer.

 This function should contain the "body" of the analysis. It can contain
 simple or elaborate selection criteria, run algorithms on the data
 of the event and typically fill histograms.

 The processing can be stopped by calling Abort().

 Use fStatus to set the return value of TTree::Process().

 The return value is currently not used.