public function setEnergy_audit_date($energy_audit_date = null)
{
// validation for constraint: string
if (!is_null($energy_audit_date) && !is_string($energy_audit_date)) {
throw new \InvalidArgumentException(sprintf('Invalid value, please provide a string, "%s" given', gettype($energy_audit_date)), __LINE__);
}
$this->energy_audit_date = $energy_audit_date;
return $this;
}