# _rename_named_args( ARGS, RENAME[, USE_DASHES[, LOWERCASE]] )
# This private method will take a hash ref as input via ARGS and copy it into a 
# new hash ref, which it returns.  During the copy, hash keys may be renamed in 
# several ways.  If LOWERCASE is true then the key is lowercase.  If USE_DASHES 
# is true then the leading character is removed if it is a dash, "-".  Finally, 
# the keys are looked up using the hash ref RENAME, and if there are matching 
# keys then the associated RENAME values are substituted.  If any key is 
# renamed to the empty string or undef then it is deleted.

sub _rename_named_args {
	my ($self, $rh_args, $rh_rename, $use_dashes, $lowercase) = @_;
	my %args_out = ();
	foreach my $key (sort keys %{$rh_args}) {
		my $value = $rh_args->{$key};
		$lowercase and $key = lc( $key );  # change to lowercase
		$use_dashes and substr( $key, 0, 1 ) eq '-' and 
			$key = substr( $key, 1 );  # remove leading "-"
		exists( $rh_rename->{$key} ) and $key = $rh_rename->{$key};  # chg alias
		$args_out{$key} = $value;
	}
	delete( $args_out{''} );  # remove unwanted elements
	return( \%args_out );
}