Invalid `Asset` object creation.
Asset object creation is invalid. The constructor of the Asset
object allows too high precision. The acceptable precision for Hive
/HBD
is 3 (.000) for VEST
is 6 (.000000).
eg:
a = tt.Asset.Hive(0.0004) # -> 0.000 HIVE
b = tt.Asset.Hive(0.0005) # -> 0.000 HIVE
c = tt.Asset.Hive(0.0006) # -> 0.001 HIVE
The correct behavior is to raise an exception when trying to create an asset
with too exact precision.