def connects_to(database: {})
      connections = []

      database.each do |role, database_key|
        config_hash = resolve_config_for_connection(database_key)
        handler = lookup_connection_handler(role.to_sym)

        connections << handler.establish_connection(config_hash)
      end

      connections
    end
def connects_to(database: {})
      connections = []

      database.each do |role, database_key|
        config_hash = resolve_config_for_connection(database_key)
        handler = lookup_connection_handler(role.to_sym)

        connections << handler.establish_connection(config_hash)
      end

      connections
    end
Connects a model to the databases specified. The +database+ keyword
 takes a hash consisting of a +role+ and a +database_key+.

 This will create a connection handler for switching between connections,
 look up the config hash using the +database_key+ and finally
 establishes a connection to that config.

   class AnimalsModel < ApplicationRecord
     self.abstract_class = true

     connects_to database: { writing: :primary, reading: :primary_replica }
   end

 Returns an array of established connections.