sub fetch_members { #	{{{1
	my $self = shift;							# get a reference to the object itself
	my @members;								# an array to hold the result
	# compose an URL
	my $url = $self->_get_graph_endpoint . "/v1.0/groups/".$self->_get_id."/members/?";
	# add a filter if needed (not doing any  filtering though)
	if ($self->_get_filter){
		$url .= $self->_get_filter."&";
	}
	# add a selectif needed, have in fact a select => see object creation
	if ($self->_get_select){
		$url .= $self->_get_select;
	}
	$url .= '&$count=true';		# adding $count just to be sure
	do_fetch($self,$url, \@members); # actual fetch is done in do_fetch()
	return  \@members; # return a reference to the resul
	
}#	}}}