old_contents: #!/usr/bin/env node
  
  require('./proof')(1, function (step, Strata, tmp, serialize, load, objectify, deepEqual) {
      var strata = new Strata({ directory: tmp, leafSize: 3, branchSize: 3 })
      step(function () {
          serialize(__dirname + '/fixtures/empties-non-pivot.before.json', tmp, step())
      }, function () {
          strata.open(step())
      }, function () {
          strata.mutator('cr', step())
      }, function (cursor) {
          step(function () {
              cursor.remove(cursor.index, step())
          }, function () {
              cursor.unlock()
          })
      }, function () {
          strata.balance(step())
      }, function () {
          objectify(tmp, step())
          load(__dirname + '/fixtures/empties-non-pivot.after.json', step())
      }, function (actual, expected) {
          deepEqual(actual, expected, 'after')
          strata.close(step())
      })
  })
  
new_contents: #!/usr/bin/env node
  
  require('./proof')(1, function (step, Strata, tmp, serialize, load, objectify, assert) {
      var strata = new Strata({ directory: tmp, leafSize: 3, branchSize: 3 })
      step(function () {
          serialize(__dirname + '/fixtures/empties-non-pivot.before.json', tmp, step())
      }, function () {
          strata.open(step())
      }, function () {
          strata.mutator('cr', step())
      }, function (cursor) {
          step(function () {
              cursor.remove(cursor.index, step())
          }, function () {
              cursor.unlock()
          })
      }, function () {
          strata.balance(step())
      }, function () {
          objectify(tmp, step())
          load(__dirname + '/fixtures/empties-non-pivot.after.json', step())
      }, function (actual, expected) {
          assert(actual, expected, 'after')
          strata.close(step())
      })
  })
  
subject: Use `assert` in `t/merge/empties-non-pivot.t.js`.