class_docstr: A persistent bag/multiset type.
  
  Requires elements to be hashable, and allows duplicates, but has no
  ordering. Bags are hashable.
  
  Do not instantiate directly, instead use the factory functions :py:func:`b`
  or :py:func:`pbag` to create an instance.
  
  Some examples:
  
  >>> s = pbag([1, 2, 3, 1])
  >>> s2 = s.add(4)
  >>> s3 = s2.remove(1)
  >>> s
  pbag([1, 1, 2, 3])
  >>> s2
  pbag([1, 1, 2, 3, 4])
  >>> s3
  pbag([1, 2, 3, 4])
docstr: Return the number of times an element appears.
  
  
  >>> pbag([]).count('non-existent')
  0
  >>> pbag([1, 1, 2]).count(1)
  2
docstr_tok: ["Return","the","number","of","times","an","element","appears",".",">",">",">","pbag","(","[","]",")",".count","(","'non-existent","'",")","0",">",">",">","pbag","(","[","1",",","1",",","2","]",")",".count","(","1",")","2"]
code: def count(self, element):
      """
      Return the number of times an element appears.
  
  
      >>> pbag([]).count('non-existent')
      0
      >>> pbag([1, 1, 2]).count(1)
      2
      """
      return self._counts.get(element, 0)
  
imports: from collections.abc import Container, Iterable, Sized, Hashable
  from functools import reduce
  from typing import Generic, TypeVar
  from pyrsistent._pmap import pmap
label_desc: Use image node_id 5 for calling the PBag obj's underlying member method code with example usage: obj.count(element) and returns: self