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/*! * Module dependencies. */
'use strict';
const mongodb = require('mongodb');const ReadPref = mongodb.ReadPreference;
/** * Converts arguments to ReadPrefs the driver * can understand. * * @param {String|Array} pref * @param {Array} [tags] */
module.exports = function readPref(pref, tags) {  if (Array.isArray(pref)) {    tags = pref[1];    pref = pref[0];  }
  if (pref instanceof ReadPref) {    return pref;  }
  switch (pref) {    case 'p':      pref = 'primary';      break;    case 'pp':      pref = 'primaryPreferred';      break;    case 's':      pref = 'secondary';      break;    case 'sp':      pref = 'secondaryPreferred';      break;    case 'n':      pref = 'nearest';      break;  }
  return new ReadPref(pref, tags);};