class_docstr: Stores position information in each posting, to allow phrase searching
  and "near" queries.
  
  Supports: frequency, weight, positions, position_boosts (always reports
  position boost = 1.0).
class_docstr_tok: ["Stores","position","information","in","each","posting",",","to","allow","phrase","searching","and","``","near","''","queries",".","Supports",":","frequency",",","weight",",","positions",",","position_boosts","(","always","reports","position","boost","=","1.0",")","."]
code: def decode_weight(self, valuestring):
      return self.decode_frequency(valuestring) * self.field_boost
  
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 5 for calling the Positions obj's underlying member method code with example usage: obj.decode_weight(valuestring) and returns: unknown