Computes a hash of an 'obj'.
Hash of a:
string is string
number is number as string
object is either result of calling $$hashKey function on the object or uniquely generated id,
that is also assigned to the $$hashKey property of the object.
Parameters
obj: any
Returns string
hash string such that the same input will have the same hash string.
The resulting string key is in 'type:hashKey' format.
Computes a hash of an 'obj'. Hash of a: string is string number is number as string object is either result of calling $$hashKey function on the object or uniquely generated id, that is also assigned to the $$hashKey property of the object.