function value(a, b, c, d) {
          assert.equal(arguments.length, 4)
          assert.deepEqual(a, mergedOptions)
          assert.deepEqual(b, otherOptions)
          assert.deepEqual(c, undefined)
          assert.deepEqual(d, otherOptions)
          calls++
        }
@param {unknown} a
@param {unknown} b
@param {unknown} c
@param {unknown} d