// Generates a valid Finnish personal identity number (in Finnish - Henkilötunnus)
echo $faker->personalIdentityNumber() // '170974-007J'
// Since the numbers are different for male and female persons, optionally you can specify gender.
echo $faker->personalIdentityNumber(\DateTime::createFromFormat('Y-m-d', '2015-12-14'), 'female') // '141215A520B'