class_docstr: Base class for Discrete distributions 
class_docstr_tok: ["Base","class","for","Discrete","distributions"]
docstr: Returns pmf of distribution at x 
docstr_tok: ["Returns","pmf","of","distribution","at","x"]
code: def pmf(self, x):
      """Returns pmf of distribution at x"""
      raise NotImplementedError("Implement in a child class.")
  
imports: from ..sampling.slice import Slice
  from ..sampling.metropolis import Metropolis, BinaryMetropolis
  from ..sampling.nuts import NoUTurnSamplerDA, LeapFrog
label_desc: Use image node_id 2 for calling the Discrete obj's underlying member method code with example usage: obj.pmf(x) without return types