assert_valid_deferrable

# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 982
          def assert_valid_deferrable(deferrable)
            return if !deferrable || %(immediate deferred).include?(deferrable)

            raise ArgumentError, "deferrable must be `:immediate` or `:deferred`, got: `#{deferrable.inspect}`"
          end