Metadata
cuprate-rpc-types also provides
some traits to access some metadata surrounding RPC data types.
For example, trait RpcCall
allows accessing whether an RPC request is restricted or not.
monerod has a boolean permission system. RPC calls can be restricted or not.
If an RPC call is restricted, it will only be allowed on un-restricted RPC servers (18081).
If an RPC call is not restricted, it will be allowed on all RPC server types (18081 & 18089).
This metadata is used in crates that build upon cuprate-rpc-types, e.g.
to know if an RPC call should be allowed through or not.