Can a return value from a function be named with a specific name for Postgraphile?
I have this function in PostgreSQL:

```
CREATE FUNCTION it_exists(
  email text,
  name text
) RETURNS boolean AS $$
DECLARE
  _eva1 boolean;
  _eva2 boolean;
BEGIN
  _eva1 := EXISTS(SELECT * FROM tableA AS A WHERE A.email = $1::citext);
  _eva2 := EXISTS(SELECT * FROM tableB AS A WHERE A.name::citext = $2::citext);
  RETURN _eva1 OR _eva2;
END;
$$ LANGUAGE plpgsql STRICT SECURITY DEFINER;
```
It is translated into Postgraphile like this:
```
mutation MyMutation($email: String!, $name: String!) {
  itExists(
    input: { email: $email, name: $name }
  ) {
    boolean
  }
}
```
I'd wish to change "boolean" name to something like "result", any suggestion? Consider I have many functions with different return values.