code: @Nullable
      @BankAccountType
      public static String asBankAccountType(@Nullable String possibleAccountType) {
          if (BankAccount.TYPE_COMPANY.equals(possibleAccountType)) {
              return BankAccount.TYPE_COMPANY;
          } else if (BankAccount.TYPE_INDIVIDUAL.equals(possibleAccountType)) {
              return BankAccount.TYPE_INDIVIDUAL;
          }
  
          return null;
      }
docs: Converts a String value into the appropriate {@link BankAccountType}.
  
  @param possibleAccountType a String that might match a {@link BankAccountType} or be empty.
  @return {@code null} if the input is blank or of unknown type, else the appropriate
  {@link BankAccountType}.