code: def delete_rdataset(self, rdclass, rdtype, covers=dns.rdatatype.NONE):
          
  
          rds = self.get_rdataset(rdclass, rdtype, covers)
          if not rds is None:
              self.rdatasets.remove(rds)
docs: Delete the rdataset matching the specified properties in the
          current node.
  
          If a matching rdataset does not exist, it is not an error.
  
          @param rdclass: The class of the rdataset
          @type rdclass: int
          @param rdtype: The type of the rdataset
          @type rdtype: int
          @param covers: The covered type.
          @type covers: int