question: returns the account number concode_field_sep String expiryDate concode_elem_sep Address address concode_elem_sep String secretCode concode_elem_sep String accountNumber concode_elem_sep Long userId concode_field_sep void setAccountNumber concode_elem_sep void setAddress concode_elem_sep String getExpiryDate concode_elem_sep void setExpiryDate concode_elem_sep String getSecretCode concode_elem_sep void setSecretCode concode_elem_sep Address getAddress
target: String function ( ) { return accountNumber ; }