invert()
  public
  
    
    
Returns a Hash (not a DBM
database) created by using each value in
the database as a key, with the corresponding key as its value.
Note that all values in the hash will
be Strings, but the keys will be actual objects.
   
  
    Show source    
    
      
    def invert
        h = {}
        keys.each { |k| h[ self.fetch( k ) ] = k }
        h
    end