## Before
```
× Checking
╰─▶ Unknown variable
Finite
╭─[../stdlib/validators/tmp.ak:10:1]
10 │ let now = when context.transaction.validity_range.lower_bound.bound_type is {
11 │ Finite { t } -> t
· ────────────
12 │ NegativeInfinity -> 0
╰────
```
## After
```
× Type-checking
╰─▶ Unknown data-type constructor 'Finite'
╭─[../stdlib/validators/tmp.ak:10:1]
10 │ let now = when context.transaction.validity_range.lower_bound.bound_type is {
11 │ Finite { t } -> t
· ────────────
12 │ NegativeInfinity -> 0
╰────
help: Did you forget to import it?
Data-type constructors are not automatically imported, even if their type is
imported. So, if a module `aiken/pet` defines the following type:
┍━ aiken/pet.ak ━━━━━━━━
│ pub type Pet {
│ Cat
│ Dog
│ }
You must import its constructors explicitly to use them, or prefix them
with the module's name.
┍━ foo.ak ━━━━━━━━
│ use aiken/pet.{Pet, Dog}
│
│ fn foo(pet : Pet) {
│ when pet is {
│ pet.Cat -> // ...
│ Dog -> // ...
│ }
│ }
```