class_docstr: A class for representing multivariate polynomial rings. 
docstr: Returns LCM of `a` and `b`. 
docstr_tok: ["Returns","LCM","of","`","a","`","and","`","b","`","."]
code: def lcm(self, a, b):
      """Returns LCM of `a` and `b`."""
      return a.lcm(b)
  
imports: from sympy.polys.domains.ring import Ring
  from sympy.polys.domains.compositedomain import CompositeDomain
  from sympy.polys.polyerrors import CoercionFailed, GeneratorsError
  from sympy.utilities import public
label_desc: Use image node_id 34 for calling the PolynomialRing obj's underlying member method code with example usage: obj.lcm(a, b) and returns: a