- a pointer to the NxsTreesBlock with index Indexing starts at 0 and refers to the index in a list of NxsTreesBlock objects that refer to the NxsTaxaBlock `taxa`. Thus, the index does not necessarily represent the position among ALL of the NxsTreesBlock objects
0L will be returned if the index is out of range. Indices should be < the number returned by GetNumTreesBlocks(taxa). If `taxa` is 0L, then the total block indexing scheme will refer to the total number of Trees blocks read.
Definition at line 584 of file nxspublicblocks.cpp.