# File lib/aws/s3/client.rb, line 991 def require_acl!(acl) validate!('acl', acl) do case when acl.kind_of?(Hash) AccessControlList.new(acl).validate! nil when !acl.respond_to?(:to_str) && !acl.respond_to?(:to_xml) "must support to_xml: #{acl.inspect}" when acl.nil? || acl == '' 'may not be blank' else xml_validation_message(acl) end end end