class_docstr: A class for representing rational function fields. 
class_docstr_tok: ["A","class","for","representing","rational","function","fields","."]
code: def __hash__(self):
      return hash(
          (self.__class__.__name__, self.dtype, self.dom, self.gens)
      )
  
imports: from sympy.polys.domains.field import Field
  from sympy.polys.domains.compositedomain import CompositeDomain
  from sympy.polys.polyclasses import DMF
  from sympy.polys.polyerrors import GeneratorsNeeded
  from sympy.polys.polyutils import dict_from_basic, basic_from_dict, _dict_reorder
  from sympy.utilities import public
label_desc: Use image node_id 5 for calling the FractionField obj's underlying member method code with example usage: obj.__hash__() and returns: hash