Required Files
- arel/errors
- arel/crud
- arel/factory_methods
- arel/expressions
- arel/predications
- arel/filter_predications
- arel/window_predications
- arel/math
- arel/alias_predication
- arel/order_predications
- arel/table
- arel/attributes/attribute
- arel/visitors
- arel/collectors/sql_string
- arel/tree_manager
- arel/insert_manager
- arel/select_manager
- arel/update_manager
- arel/delete_manager
- arel/nodes