code: def getatom(self, atomends=None):
          
          atomlist = ['']
          if atomends is None:
              atomends = self.atomends
  
          while self.pos < len(self.field):
              if self.field[self.pos] in atomends:
                  break
              else:
                  atomlist.append(self.field[self.pos])
              self.pos += 1
  
          return EMPTYSTRING.join(atomlist)
docs: Parse an RFC 2822 atom.
  
          Optional atomends specifies a different set of end token delimiters
          (the default is to use self.atomends).  This is used e.g. in
          getphraselist() since phrase endings must not include the `.' (which
          is legal in phrases).