class_docstr: Stores frequency information for each posting.
  
  Supports: frequency, weight.
class_docstr_tok: ["Stores","frequency","information","for","each","posting",".","Supports",":","frequency",",","weight","."]
code: def decode_weight(self, valuestring):
      freq = unpack_uint(valuestring)[0]
      return freq * 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 4 for calling the Frequency obj's underlying member method code with example usage: obj.decode_weight(valuestring) and returns: unknown