Query data provider service in
Raise error if Bitcoin transaction fee is unreasonable.
The change to 21 doctor was interesting to me because I learned that TWO1_PROVIDER_HOST is a configurable value for “21 Blockchain Provider”, in other words, perhaps there may be 21 Blockchain Providers other than 21.co. This sheds some light on 21’s enterprise strategy.
By looking at the code for determining unreasonable fees I discovered (if I am reading this correctly) that 21 will raise a warning if the calculated fee is more than twice the default fee per byte. This seems reasonable …
if not 0 <= fee_per_kb <= 2 * DEFAULT_FEE_PER_KB: raise exceptions.UnreasonableFeeError( 'Unreasonable fee per kB: %s' % fee_per_kb)