module ActiveFedora::Core

def initialize_attributes attributes_or_id
  case attributes_or_id
    when String
      attributes = {id: attributes_or_id}.with_indifferent_access
    when Hash
      attributes = attributes_or_id.with_indifferent_access
      # TODO: Remove when we decide using 'pid' is no longer supported.
      if !attributes.key?(:id) && attributes.key?(:pid)
        Deprecation.warn Core, 'Initializing with :pid is deprecated and will be removed in active-fedora 10.0. Use :id instead'
        attributes[:id] = attributes.delete(:pid)
      end
    when NilClass
      attributes = {}.with_indifferent_access
    else
      raise ArgumentError, "#{attributes_or_id.class} is not acceptable"
  end
  return attributes
end