prompt: You will be provided with a partial code base and an issue statement explaining a problem to resolve.
  <issue>
  Capture Celery Time-in-queue
  
  
  </issue>
  <code>
  [start of src/scout_apm/celery.py]
  1 # coding=utf-8
  2 from __future__ import absolute_import, division, print_function, unicode_literals
  3 
  4 from celery.signals import task_postrun, task_prerun
  5 
  6 import scout_apm.core
  7 from scout_apm.core.tracked_request import TrackedRequest
  8 
  9 
  10 def prerun_callback(task=None, **kwargs):
  11     tracked_request = TrackedRequest.instance()
  12     tracked_request.mark_real_request()
  13 
  14     delivery_info = task.request.delivery_info
  15     tracked_request.tag("is_eager", delivery_info.get("is_eager", False))
  16     tracked_request.tag("exchange", delivery_info.get("exchange", "unknown"))
  17     tracked_request.tag("routing_key", delivery_info.get("routing_key", "unknown"))
  18     tracked_request.tag("queue", delivery_info.get("queue", "unknown"))
  19 
  20     tracked_request.start_span(operation=("Job/" + task.name))
  21 
  22 
  23 def postrun_callback(task=None, **kwargs):
  24     tracked_request = TrackedRequest.instance()
  25     tracked_request.stop_span()
  26 
  27 
  28 def install():
  29     installed = scout_apm.core.install()
  30     if not installed:
  31         return
  32 
  33     task_prerun.connect(prerun_callback)
  34     task_postrun.connect(postrun_callback)
  35 
  36 
  37 def uninstall():
  38     task_prerun.disconnect(prerun_callback)
  39     task_postrun.disconnect(postrun_callback)
  40
  [end of src/scout_apm/celery.py]
  </code>
  
  I need you to solve this issue by generating a single patch file that I can apply directly to this repository using git apply. Please respond with a single patch file in the following format.
  <patch>
  diff --git a/file.py b/file.py
  --- a/file.py
  +++ b/file.py
  @@ -1,27 +1,35 @@
   def euclidean(a, b):
  -    while b:
  -        a, b = b, a % b
  -    return a
  +    if b == 0:
  +        return a
  +    return euclidean(b, a % b)
   
   
   def bresenham(x0, y0, x1, y1):
       points = []
       dx = abs(x1 - x0)
       dy = abs(y1 - y0)
  -    sx = 1 if x0 < x1 else -1
  -    sy = 1 if y0 < y1 else -1
  -    err = dx - dy
  +    x, y = x0, y0
  +    sx = -1 if x0 > x1 else 1
  +    sy = -1 if y0 > y1 else 1
   
  -    while True:
  -        points.append((x0, y0))
  -        if x0 == x1 and y0 == y1:
  -            break
  -        e2 = 2 * err
  -        if e2 > -dy:
  -            err -= dy
  -            x0 += sx
  -        if e2 < dx:
  -            err += dx
  -            y0 += sy
  +    if dx > dy:
  +        err = dx / 2.0
  +        while x != x1:
  +            points.append((x, y))
  +            err -= dy
  +            if err < 0:
  +                y += sy
  +                err += dx
  +            x += sx
  +    else:
  +        err = dy / 2.0
  +        while y != y1:
  +            points.append((x, y))
  +            err -= dx
  +            if err < 0:
  +                x += sx
  +                err += dy
  +            y += sy
  +
  +    points.append((x, y))
       return points
  
  </patch>
golden_diff: diff --git a/src/scout_apm/celery.py b/src/scout_apm/celery.py
  --- a/src/scout_apm/celery.py
  +++ b/src/scout_apm/celery.py
  @@ -1,16 +1,34 @@
   # coding=utf-8
   from __future__ import absolute_import, division, print_function, unicode_literals
   
  -from celery.signals import task_postrun, task_prerun
  +import datetime as dt
  +
  +from celery.signals import before_task_publish, task_postrun, task_prerun
   
   import scout_apm.core
  +from scout_apm.compat import datetime_to_timestamp
   from scout_apm.core.tracked_request import TrackedRequest
   
   
  +def before_publish_callback(headers=None, properties=None, **kwargs):
  +    if "scout_task_start" not in headers:
  +        headers["scout_task_start"] = datetime_to_timestamp(dt.datetime.utcnow())
  +
  +
   def prerun_callback(task=None, **kwargs):
       tracked_request = TrackedRequest.instance()
       tracked_request.mark_real_request()
   
  +    start = getattr(task.request, "scout_task_start", None)
  +    if start is not None:
  +        now = datetime_to_timestamp(dt.datetime.utcnow())
  +        try:
  +            queue_time = now - start
  +        except TypeError:
  +            pass
  +        else:
  +            tracked_request.tag("queue_time", queue_time)
  +
       delivery_info = task.request.delivery_info
       tracked_request.tag("is_eager", delivery_info.get("is_eager", False))
       tracked_request.tag("exchange", delivery_info.get("exchange", "unknown"))
  @@ -30,10 +48,12 @@
       if not installed:
           return
   
  +    before_task_publish.connect(before_publish_callback)
       task_prerun.connect(prerun_callback)
       task_postrun.connect(postrun_callback)
   
   
   def uninstall():
  +    before_task_publish.disconnect(before_publish_callback)
       task_prerun.disconnect(prerun_callback)
       task_postrun.disconnect(postrun_callback)
  
verification_info: {"golden_diff": "diff --git a/src/scout_apm/celery.py b/src/scout_apm/celery.py\n--- a/src/scout_apm/celery.py\n+++ b/src/scout_apm/celery.py\n@@ -1,16 +1,34 @@\n # coding=utf-8\n from __future__ import absolute_import, division, print_function, unicode_literals\n \n-from celery.signals import task_postrun, task_prerun\n+import datetime as dt\n+\n+from celery.signals import before_task_publish, task_postrun, task_prerun\n \n import scout_apm.core\n+from scout_apm.compat import datetime_to_timestamp\n from scout_apm.core.tracked_request import TrackedRequest\n \n \n+def before_publish_callback(headers=None, properties=None, **kwargs):\n+    if \"scout_task_start\" not in headers:\n+        headers[\"scout_task_start\"] = datetime_to_timestamp(dt.datetime.utcnow())\n+\n+\n def prerun_callback(task=None, **kwargs):\n     tracked_request = TrackedRequest.instance()\n     tracked_request.mark_real_request()\n \n+    start = getattr(task.request, \"scout_task_start\", None)\n+    if start is not None:\n+        now = datetime_to_timestamp(dt.datetime.utcnow())\n+        try:\n+            queue_time = now - start\n+        except TypeError:\n+            pass\n+        else:\n+            tracked_request.tag(\"queue_time\", queue_time)\n+\n     delivery_info = task.request.delivery_info\n     tracked_request.tag(\"is_eager\", delivery_info.get(\"is_eager\", False))\n     tracked_request.tag(\"exchange\", delivery_info.get(\"exchange\", \"unknown\"))\n@@ -30,10 +48,12 @@\n     if not installed:\n         return\n \n+    before_task_publish.connect(before_publish_callback)\n     task_prerun.connect(prerun_callback)\n     task_postrun.connect(postrun_callback)\n \n \n def uninstall():\n+    before_task_publish.disconnect(before_publish_callback)\n     task_prerun.disconnect(prerun_callback)\n     task_postrun.disconnect(postrun_callback)\n", "issue": "Capture Celery Time-in-queue\n\n", "before_files": [{"content": "# coding=utf-8\nfrom __future__ import absolute_import, division, print_function, unicode_literals\n\nfrom celery.signals import task_postrun, task_prerun\n\nimport scout_apm.core\nfrom scout_apm.core.tracked_request import TrackedRequest\n\n\ndef prerun_callback(task=None, **kwargs):\n    tracked_request = TrackedRequest.instance()\n    tracked_request.mark_real_request()\n\n    delivery_info = task.request.delivery_info\n    tracked_request.tag(\"is_eager\", delivery_info.get(\"is_eager\", False))\n    tracked_request.tag(\"exchange\", delivery_info.get(\"exchange\", \"unknown\"))\n    tracked_request.tag(\"routing_key\", delivery_info.get(\"routing_key\", \"unknown\"))\n    tracked_request.tag(\"queue\", delivery_info.get(\"queue\", \"unknown\"))\n\n    tracked_request.start_span(operation=(\"Job/\" + task.name))\n\n\ndef postrun_callback(task=None, **kwargs):\n    tracked_request = TrackedRequest.instance()\n    tracked_request.stop_span()\n\n\ndef install():\n    installed = scout_apm.core.install()\n    if not installed:\n        return\n\n    task_prerun.connect(prerun_callback)\n    task_postrun.connect(postrun_callback)\n\n\ndef uninstall():\n    task_prerun.disconnect(prerun_callback)\n    task_postrun.disconnect(postrun_callback)\n", "path": "src/scout_apm/celery.py"}]}