+class EnumValue(object):
+
+ _enum_values = {}
+
+ def __new__(cls, id):
+ if cls not in cls._enum_values:
+ cls._enum_values[cls] = {}
+ if id not in cls._enum_values[cls]:
+ value = super(EnumValue, cls).__new__(cls)
+ value.id = id
+ cls._enum_values[cls][id] = value
+ return cls._enum_values[cls][id]
+
+class LogLevel(EnumValue):
+ pass
+
+class PacketType(EnumValue):
+ pass
+
+class Quantity(EnumValue):
+ pass
+
+class Unit(EnumValue):
+ pass
+
+class QuantityFlag(EnumValue):
+
+ @classmethod
+ def set_from_mask(cls, mask):
+ result = set()
+ while mask:
+ new_mask = mask & (mask - 1)
+ result.add(cls(mask ^ new_mask))
+ mask = new_mask
+ return result
+