text: module.exports = tag
  
  var assert = require('assert')
  
  function tag(uri, params, cb) {
      assert(typeof uri === 'string', 'must pass registry URI to tag')
      assert(params && typeof params === 'object', 'must pass params to tag')
      assert(typeof cb === 'function', 'must pass callback to tag')
  
      assert(typeof params.version === 'string', 'must pass version to tag')
      assert(typeof params.tag === 'string', 'must pass tag name to tag')
      assert(
          params.auth && typeof params.auth === 'object',
          'must pass auth to tag'
      )
  
      var options = {
          method: 'PUT',
          body: JSON.stringify(params.version),
          auth: params.auth
      }
      this.request(uri + '/' + params.tag, options, cb)
  }
  