code: function createLogger(logger) {
      var result = logger ? objectAssign({}, logger) : {};
      if (!result.debug) result.debug = console.log;
      if (!result.info) result.info = console.info;
      if (!result.warn) result.warn = console.warn;
      if (!result.error) result.error = console.error;
      return result;
  }
docs: create a logger object based on passed logger. If passed logger has no some methods then add them
  
  @param {Object} [logger] object with methods .debug, .warn, .error. Can be
  @return {Object}