class_docstr: A class for representing multivariate polynomial rings. 
docstr: Convert a polynomial to ``dtype``. 
docstr_tok: ["Convert","a","polynomial","to","``","dtype","``","."]
code: def from_PolynomialRing(K1, a, K0):
      """Convert a polynomial to ``dtype``."""
      try:
          return a.set_ring(K1.ring)
      except (CoercionFailed, GeneratorsError):
          return None
  
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 24 for calling the PolynomialRing obj's underlying member method code with example usage: obj.from_PolynomialRing(K1, a, K0) and returns: a, None