code: def find_rrset(self, section, name, rdclass, rdtype,
                     covers=dns.rdatatype.NONE, deleting=None, create=False,
                     force_unique=False):
          
  
          key = (self.section_number(section),
                 name, rdclass, rdtype, covers, deleting)
          if not force_unique:
              if not self.index is None:
                  rrset = self.index.get(key)
                  if not rrset is None:
                      return rrset
              else:
                  for rrset in section:
                      if rrset.match(name, rdclass, rdtype, covers, deleting):
                          return rrset
          if not create:
              raise KeyError
          rrset = dns.rrset.RRset(name, rdclass, rdtype, covers, deleting)
          section.append(rrset)
          if not self.index is None:
              self.index[key] = rrset
          return rrset
docs: Find the RRset with the given attributes in the specified section.
  
          @param section: the section of the message to look in, e.g.
          self.answer.
          @type section: list of dns.rrset.RRset objects
          @param name: the name of the RRset
          @type name: dns.name.Name object
          @param rdclass: the class of the RRset
          @type rdclass: int
          @param rdtype: the type of the RRset
          @type rdtype: int
          @param covers: the covers value of the RRset
          @type covers: int
          @param deleting: the deleting value of the RRset
          @type deleting: int
          @param create: If True, create the RRset if it is not found.
          The created RRset is appended to I{section}.
          @type create: bool
          @param force_unique: If True and create is also True, create a
          new RRset regardless of whether a matching RRset exists already.
          @type force_unique: bool
          @raises KeyError: the RRset was not found and create was False
          @rtype: dns.rrset.RRset object