class_docstr: Stores token position and character start and end information for each
  posting.
  
  Supports: frequency, weight, positions, position_boosts (always reports
  position boost = 1.0), characters.
class_docstr_tok: ["Stores","token","position","and","character","start","and","end","information","for","each","posting",".","Supports",":","frequency",",","weight",",","positions",",","position_boosts","(","always","reports","position","boost","=","1.0",")",",","characters","."]
code: def encode(self, poslist):
      deltas = []
      posbase = 0
      charbase = 0
      for pos, startchar, endchar in poslist:
          deltas.append(
              (pos - posbase, startchar - charbase, endchar - startchar)
          )
          posbase = pos
          charbase = endchar
      return pack_uint(len(deltas)) + dumps(deltas, 2)
  
imports: from collections import defaultdict
  from whoosh.analysis import unstopped, entoken
  from whoosh.compat import iteritems, dumps, loads, b
  from whoosh.system import emptybytes
  from whoosh.system import _INT_SIZE, _FLOAT_SIZE
  from whoosh.system import pack_uint, unpack_uint, pack_float, unpack_float
label_desc: Use image node_id 2 for calling the Characters obj's underlying member method code with example usage: obj.encode(poslist) and returns: unknown