class_docstr: Stores draws from one or more chains.
  
  Returned by methods of a ``Model``. Users will not instantiate this class directly.
  
  A `Fit` instance works like a Python dictionary. A user-friendly views of draws
  is available via ``to_frame``.
code: def __len__(self) -> int:
      return len(self.param_names)
  
file_path: pystan/stan/fit.py
imports: import collections
  import json
  from math import ceil
  from typing import Generator, Tuple, cast
  import numpy
  import simdjson
label_desc: Use image node_id 6 for calling the Fit obj's underlying member method code with example usage: obj.__len__() and returns: len