adding utility class

Author: mvexel

overpass/__init__.py

@@ -11,3 +11,4 @@
 from .errors import (
     OverpassError, OverpassSyntaxError, TimeoutError, MultipleRequestsError, ServerLoadError, UnknownOverpassError
 )
+from .utils import *

overpass/utils.py

@@ -0,0 +1,9 @@
+class Utils(object):
+
+	@classmethod
+	def to_overpass_id(self, osmid, area=False):
+		AREA_BASE = 2400000000
+		RELATION_BASE = 3600000000
+		if area:
+			return int(osmid) + AREA_BASE
+		return int(osmid) + RELATION_BASE