class_docstr: Discrete Uniform Distribution 
class_docstr_tok: ["Discrete","Uniform","Distribution"]
docstr: Returns pmf of distribution at x. 
code: def pmf(self, x):
      """Returns pmf of distribution at x."""
      if x >= self.lower and x <= self.upper:
          return 1 / (self.upper - self.lower + 1)
      return 0
  
imports: from __future__ import absolute_import
  import numpy
  from .distribution import Discrete
  from ..exd import domains
label_desc: Use image node_id 2 for calling the DiscreteUniform obj's underlying member method code with example usage: obj.pmf(x) and returns: int, unknown