In Move, We define errors as constants that are of type u64. Ensure to add comments above each of the errors. This creates human-readable error messages returned by APIs. Type these in below the dependencies we defined in the "Pre-requisites" section.

/// Caller is not authorized to make this call
const EUNAUTHORIZED: u64 = 1;
/// No operations are allowed when contract is paused
const EPAUSED: u64 = 2;
/// The account is already a minter
const EALREADY_MINTER: u64 = 3;
/// The account is not a minter
const ENOT_MINTER: u64 = 4;
/// The account is denylisted
const EBLACKLISTED: u64 = 5;

Next, We will create an asset symbol constant to use as a seed for our named object. Constant strings have the vector<u8> type.

const ASSET_SYMBOL: vector<u8> = b"USDK";