sub param {
    my $self = shift;
    my (@data) = (@_);

    # First use?  Create new __PARAMS!
    $self->{__PARAMS} = {} unless (exists($self->{__PARAMS}));

    my $rp = $self->{__PARAMS};

    # If data is provided, set it!
    if (scalar(@data)) {
        # Is it a hash, or hash-ref?
        if (ref($data[0]) eq 'HASH') {
            # Make a copy, which augments the existing contents (if any)
            %$rp = (%$rp, %{$data[0]});
        } elsif ((scalar(@data) % 2) == 0) {
            # It appears to be a possible hash (even # of elements)
            %$rp = (%$rp, @data);
        } elsif (scalar(@data) > 1) {
            croak("Odd number of elements passed to param().  Not a valid hash");
        }
    } else {
        # Return the list of param keys if no param is specified.
        return (keys(%$rp));
    }

    # If exactly one parameter was sent to param(), return the value
    if (scalar(@data) <= 2) {
        my $param = $data[0];
        return $rp->{$param};
    }
    return;  # Otherwise, return undef
} # /param