question: private static final Map < Id < Link > , Id < Zone > > parseL2ZMapping ( String infile ) { Map < Id < Link > , Id < Zone > > l2zMapping = new HashMap < > ( ) ; try { FileReader fr = new FileReader ( infile ) ; BufferedReader br = new BufferedReader ( fr ) ; String curr_line ; while ( ( curr_line = br . readLine ( ) ) != null ) { String [ ] entries = curr_line . split ( "\t" , - 1 ) ; Id < Link > lid = Id . create ( entries [ 0 ] , Link . class ) ; Id < Zone > zid = Id . create ( entries [ 1 ] , Zone . class ) ; l2zMapping . put ( lid , zid ) ; } } catch ( IOException e ) { throw new RuntimeException ( e ) ; } return l2zMapping ; }
target:  This method, if I am seeing this right, is meant to parse a file that contains the mapping from links to zones (assuming that linkIds are in column 0, and zones in column 1). But it will presumably parse any two columns of a column-oriented file.