test_that("parallel", {
  do <- async(function() {
    dx1 <- http_get(http$url("/get", query = list(q = "foo")))$then(
      function(.) rawToChar(.$content)
    )
    dx2 <- http_get(http$url("/get", query = list(q = "bar")))$then(
      function(.) rawToChar(.$content)
    )

    when_all(
      dx1$then(function(.) expect_match(., "\"q\":[ ]*\"foo\"")),
      dx2$then(function(.) expect_match(., "\"q\":[ ]*\"bar\""))
    )
  })
  synchronise(do())
})