• benchmark
• set
• zlib
• active_support/core_ext/array/access
• active_support/core_ext/enumerable
• active_support/core_ext/module/attribute_accessors
• active_support/actionable_error
• active_record/migration/pending_migration_connection

• 模块 ActiveRecord
• 模块 ActiveRecord::ConnectionHandling
• 模块 ActiveRecord::Tasks
• 模块 ActiveRecord::VERSION
• 类 ActiveRecord::EnvironmentMismatchError
• 类 ActiveRecord::IrreversibleMigration
• 类 ActiveRecord::Migration
• 类 ActiveRecord::Migration::CheckPending
• 类 ActiveRecord::MigrationContext