nullToString() public static method

public static nullToString ( String str ) : String
str String
return String
 public ContactInfo(String firstName, String lastName, String phone,
                    String email, String street, String city, String state,
                    String postalcode, String country)
 {
     this.firstName  = Utilities.nullToString(firstName);
     this.lastName   = Utilities.nullToString(lastName);
     this.phone      = Utilities.nullToString(phone);
     this.email      = Utilities.nullToString(email);
     this.street     = Utilities.nullToString(street);
     this.city       = Utilities.nullToString(city);
     this.state      = Utilities.nullToString(state);
     this.postalcode = Utilities.nullToString(postalcode);
     this.country    = Utilities.nullToString(country);
 }
 public CreditCard(String number, String type, DateTime date)
 {
     this.number = Utilities.nullToString(number);
     this.type   = Utilities.nullToString(type);
     this.date   = date;
 }