question: private static long sublong ( String value , int begin_index , int end_index ) { String substring = value . substring ( begin_index , end_index ) ; return ( substring . length ( ) > 0 ) ? Long . parseLong ( substring ) : - 1 ; }
target:  Returns a substring of the given string value from the given begin index to the given end index as a long. If the substring is empty, then -1 will be returned.