code: public static void checkDatabaseNameValidity(final String databaseName) {
          notNull("databaseName", databaseName);
          isTrueArgument("databaseName is not empty", !databaseName.isEmpty());
          for (int i = 0; i < databaseName.length(); i++) {
              isTrueArgument("databaseName does not contain '" + databaseName.charAt(i) + "'",
                      !PROHIBITED_CHARACTERS_IN_DATABASE_NAME.contains(databaseName.charAt(i)));
          }
      }
docs: Check the validity of the given database name. A valid database name is non-null, non-empty, and does not contain any of the
  following characters: {@code '\0', '/', '\\', ' ', '"', '.'}. The server may impose additional restrictions on database names.
  
  @param databaseName the database name
  @throws IllegalArgumentException if the database name is invalid
  @since 3.4
  @mongodb.driver.manual reference/limits/#naming-restrictions Naming Restrictions