module Doorkeeper::GrantFlow::Registry

def expand_alias(alias_name) 

def expand_alias(alias_name)
  aliases.fetch(alias_name.to_sym, [])
end

def get(name)

[NOTE]: make it to use #fetch after removing fallbacks 
def get(name)
  flows[name.to_sym]
end

def register(name_or_flow, **options)


could recognize and process it.
Allows to register custom OAuth grant flow so that Doorkeeper 
def register(name_or_flow, **options)
  unless name_or_flow.is_a?(Doorkeeper::GrantFlow::Flow)
    name_or_flow = Flow.new(name_or_flow, **options)
  end
  flow_key = name_or_flow.name.to_sym
  if flows.key?(flow_key)
    ::Kernel.warn <<~WARNING
      [DOORKEEPER] '#{flow_key}' grant flow already registered and will be overridden
      in #{caller(1..1).first}
    WARNING
  end
  flows[flow_key] = name_or_flow
end

def register_alias(alias_name, **options)


1:N, i.e. "implicit_oidc" => ['token', 'id_token', 'id_token token'].
configuration option. It is possible to have aliases like 1:1 or
Allows to register aliases that could be used in `grant_flows` 
def register_alias(alias_name, **options)
  aliases[alias_name.to_sym] = Array.wrap(options.fetch(:as))
end