wip: Add address reputation

This adds support for fetching an address' reputation lazily.

TODO:
* Add unit tests

Example:
```
risky_address = Coinbase::Address.new(:ethereum_mainnet, '0x12846c6Fd6baBFE4bC6F761eB871eFfFDEb26913')

// Returns the reputation of the address
risky_address.reputation

// Returns whether the address itself is deemed "risky"
risky_address.risky?
=> true
```

lib/coinbase.rb

@@ -1,15 +1,16 @@
 # frozen_string_literal: true
 
+require_relative 'coinbase/client'
 require_relative 'coinbase/address'
 require_relative 'coinbase/address/wallet_address'
 require_relative 'coinbase/address/external_address'
+require_relative 'coinbase/address_reputation'
 require_relative 'coinbase/asset'
 require_relative 'coinbase/authenticator'
 require_relative 'coinbase/correlation'
 require_relative 'coinbase/balance'
 require_relative 'coinbase/balance_map'
 require_relative 'coinbase/historical_balance'
-require_relative 'coinbase/client'
 require_relative 'coinbase/constants'
 require_relative 'coinbase/contract_event'
 require_relative 'coinbase/contract_invocation'

lib/coinbase/address.rb

@@ -17,7 +17,14 @@ def initialize(network, id)
     # Returns a String representation of the Address.
     # @return [String] a String representation of the Address
     def to_s
-      Coinbase.pretty_print_object(self.class, id: id, network_id: network.id)
+      Coinbase.pretty_print_object(
+        self.class,
+        **{
+          id: id,
+          network_id: network.id,
+          reputation_score: @reputation.nil? ? nil : reputation.score,
+        }.compact
+      )
     end
 
     # Same as to_s.
@@ -32,6 +39,18 @@ def can_sign?
       false
     end
 
+    # Returns the reputation of the Address.
+    # @return [Coinbase::AddressReputation] The reputation of the Address
+    def reputation
+      @reputation ||= Coinbase::AddressReputation.fetch(network: network, address_id: id)
+    end
+
+    # Returns wheth the Address's reputation is risky.
+    # @return [Boolean] true if the Address's reputation is risky
+    def risky?
+      reputation.risky?
+    end
+
     # Returns the balances of the Address.
     # @return [BalanceMap] The balances of the Address, keyed by asset ID. Ether balances are denominated
     #  in ETH.
@@ -66,7 +85,7 @@ def balance(asset_id)
     # @return [Enumerable<Coinbase::HistoricalBalance>] Enumerator that returns historical_balance
     def historical_balances(asset_id)
       Coinbase::Pagination.enumerate(
-        ->(page) { list_page(asset_id, page) }
+        ->(page) { list_historical_balance_page(asset_id, page) }
       ) do |historical_balance|
         Coinbase::HistoricalBalance.from_model(historical_balance)
       end
@@ -265,7 +284,11 @@ def stake_api
       @stake_api ||= Coinbase::Client::StakeApi.new(Coinbase.configuration.api_client)
     end
 
-    def list_page(asset_id, page)
+    def reputation_api
+      @reputation_api ||= Coinbase::Client::ReputationApi.new(Coinbase.configuration.api_client)
+    end
+
+    def list_historical_balance_page(asset_id, page)
       balance_history_api.list_address_historical_balance(
         network.normalized_id,
         id,
@@ -281,5 +304,13 @@ def list_transaction_page(page)
         { limit: DEFAULT_TRANSACTION_PAGE_LIMIT, page: page }
       )
     end
+
+    def get_reputation
+      response = Coinbase.call_api do
+        reputation_api.get_address_reputation(network.normalized_id, id)
+      end
+
+      response
+    end
   end
 end

lib/coinbase/address_reputation.rb

@@ -0,0 +1,70 @@
+# frozen_string_literal: true
+
+module Coinbase
+  # A representation of the reputation of a blockchain address.
+  class AddressReputation
+    # A metadata object associated with an address reputation.
+    Metadata = Struct.new(
+      *Client::AddressReputationMetadata.attribute_map.keys.map(&:to_sym),
+      keyword_init: true
+    ) do
+      def to_s
+        Coinbase.pretty_print_object(
+          self.class,
+          **to_h
+        )
+      end
+    end
+
+    class << self
+      def fetch(address_id:, network: Coinbase.default_network)
+        network = Coinbase::Network.from_id(network)
+
+        model = Coinbase.call_api do
+          reputation_api.get_address_reputation(network.normalized_id, address_id)
+        end
+
+        new(model)
+      end
+
+      private
+
+      def reputation_api
+        Coinbase::Client::ReputationApi.new(Coinbase.configuration.api_client)
+      end
+    end
+
+    def initialize(model)
+      unless model.is_a?(Coinbase::Client::AddressReputation)
+        raise ArgumentError,
+              'must be an AddressReputation client object'
+      end
+
+      @model = model
+    end
+
+    def score
+      @model.score
+    end
+
+    def metadata
+      @metadata ||= Metadata.new(**@model.metadata)
+    end
+
+    def risky?
+      score.negative?
+    end
+
+    def to_s
+      Coinbase.pretty_print_object(
+        self.class,
+        score: score,
+        **metadata.to_h
+      )
+    end
+
+    def inspect
+      to_s
+    end
+  end
+end