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##### SUMMARY
<!--- Explain the problem briefly below -->
Ansible currently contains two modules for managing AWS EC2 instances: [`ec2`](https://docs.ansible.com/ansible/latest/modules/ec2_module.html) and [`ec2_instance`](https://docs.ansible.com/ansible/latest/modules/ec2_instance_module.html).

There is considerable overlap between the modules, but it's unclear what the differences are and why there are two modules in the first place.

##### ISSUE TYPE
- Documentation Report

##### COMPONENT NAME
<!--- Write the short name of the module, plugin, task or feature below, use your best guess if unsure -->
ec2
ec2_instance

##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```paste below
ansible 2.10.0.dev0
  config file = /home/user/.ansible.cfg
  configured module search path = ['/home/user/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /home/user/ansible/lib/ansible
  executable location = /home/user/ansible/bin/ansible
  python version = 3.7.5 (default, Oct 27 2019, 15:43:29) [GCC 9.2.1 20191022]
```

##### CONFIGURATION
<!--- Paste verbatim output from "ansible-config dump --only-changed" between quotes -->
```paste below
RETRY_FILES_ENABLED(/home/user/.ansible.cfg) = False
```

##### OS / ENVIRONMENT
<!--- Provide all relevant information below, e.g. target OS versions, network device firmware, etc. -->
Debian bullseye/sid

##### STEPS TO REPRODUCE
<!--- Describe exactly how to reproduce the problem, using a minimal test-case -->

<!--- Paste example playbooks or commands between quotes below -->
```yaml
N/A
```

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##### EXPECTED RESULTS
<!--- Describe what you expected to happen when running the steps above -->
N/A

##### ACTUAL RESULTS
<!--- Describe what actually happened. If possible run with extra verbosity (-vvvv) -->

<!--- Paste verbatim command output between quotes -->
```paste below
N/A
```

instance_dict_array.append(get_instance_info(inst))
                try:
                    if state == 'running':
                        inst.start()
                    else:
                        inst.stop()
                except EC2ResponseError as e:
                    module.fail_json(msg='Unable to change state for instance {0}, error: {1}'.format(inst.id, e))
                changed = True
            existing_instances_array.append(inst.id)
    instance_ids = list(set(existing_instances_array + (instance_ids or [])))
    
    wait_timeout = time.time() + wait_timeout
    while wait and wait_timeout > time.time():
        instance_dict_array = []
        matched_instances = []
        for res in ec2.get_all_instances(instance_ids):
            for i in res.instances:
                if i.state == state:
                    instance_dict_array.append(get_instance_info(i))
                    matched_instances.append(i)
        if len(matched_instances) < len(instance_ids):
            time.sleep(5)
        else:
            break
    if wait and wait_timeout <= time.time():
        
        module.fail_json(msg="wait for instances running timeout on %s" % time.asctime())
    return (changed, instance_dict_array, instance_ids)
def restart_instances(module, ec2, instance_ids, state, instance_tags):