code: function(sq_prefixes) {
  		var s_select = this.select || '*';
  		var sq_select = 'SELECT '+s_select+' WHERE {';
  		var sq_where = this.where;
  		var sq_tail = this.tail;
  		var sq_group = this.group? ' GROUP BY '+this.group: '';
  		var sq_order = this.order? ' ORDER BY '+this.order: '';
  		var sq_limit_offset = this.limit;
  		var sq_close = '\n}';
  		return ''
  			+sq_prefixes
  			+sq_select
  			+sq_where
  			+sq_tail
  			+sq_close
  			+sq_group
  			+sq_order
  			+sq_limit_offset;
  	}
docs: converts query hash to sparql string