How to pause between tests to do a common task, then resume for assert in tests

Currently I have a scenario where there is a resource intensive task occurring in each test. What I want to do is make this task execute after all tests have generated and pause between executions. Then finally assert a condition. For example currently I have the task (let's say foo) running. This is currently executed as:

foo(var):
  SendAPIrequest_to_store(val) #--->> this takes a long time

test_A():
  var = generated data
  foo(var)
  assert generated data present in server

test_B():
  var = generated value
  foo(var)
  assert generated data present in server

....

test_X():
  var = generated value
  foo(var)
  assert generated data present in server

This server can, let's say add multiple data at once - hence instead of running the whole task individually, I am looking for a way to achieve the following behaviour:

add_data(x):
  val = val + "," + x

foo(var):
  # this function will be run after all the test data has been added with all tests currently being suspended till generation
  SendAPIrequest_to_store(val) #----> this takes a long time
  # now we will continue the execution for the tests from where it was paused in sequence
  # so assert data for test_A then continue assertion for test_B and so-on



test_A():
  var = generated data
  add_data(var)
  PAUSE and move to the next test
  assert generated data present in server

test_B():
  var = generated value
  add_data(var)
  PAUSE and move to the next test
  assert generated data present in server

....

test_X():
  var = generated value
  add_data(var)
  PAUSE and move to the next test
  assert generated data present in server

Any help or pointers will be greatly appreciated. Thank you in advance

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