code: public CommandResult command(final String command, final ReadPreference readPreference) {
          return command(new BasicDBObject(command, true), readPreference);
      }
docs: Executes a database command. This method constructs a simple {@link DBObject} and calls {@link DB#command(DBObject, ReadPreference)
  }.
  
  @param command        The name of the command to be executed
  @param readPreference Where to execute the command - this will only be applied for a subset of commands
  @return The result of the command execution
  @throws MongoException if the command failed
  @mongodb.driver.manual tutorial/use-database-commands Commands
  @since 2.12