TITLE: Defining UDT and UDTPausable Traits in Rust DESCRIPTION: This snippet defines the `UDT` and `UDTPausable` public module traits in Rust, which are part of the `ckb_ssri_sdk`. The `UDT` trait specifies standard UDT operations like balance, transfer, and mint, while the `UDTPausable` trait extends `UDT` by adding functionalities such as pause, unpause, and checking pause status. These traits provide a standardized interface for SSRI-compliant contracts, enabling discoverability and predictable interactions for dApps and infrastructure. SOURCE: https://github.com/alive24/pausable-udt/blob/master/README.md#_snippet_0 LANGUAGE: Rust CODE: ``` pub trait UDT { type Error; fn balance() -> Result; fn transfer( tx: Option, to_lock_vec: Vec