pub fn line_keylet(
_env: wasm_exec_env_t,
account1_ptr: *const u8,
account1_len: usize,
account2_ptr: *const u8,
account2_len: usize,
currency_ptr: *const u8,
currency_len: usize,
out_buf_ptr: *mut u8,
out_buf_cap: usize,
) -> i32