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##### SUMMARY
Documentation states, that uuid is required if name is not set but the play fails with an error that a required argument (name) is missing.

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
vmware_guest_custom_attributes

##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```
$ ansible --version
ansible 2.8.5
  config file = /Users/oha/.ansible.cfg
  configured module search path = ['/Users/oha/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /Users/oha/venv/ansible/lib/python3.7/site-packages/ansible
  executable location = /Users/oha/venv/ansible/bin/ansible
  python version = 3.7.4 (default, Sep  7 2019, 18:27:02) [Clang 10.0.1 (clang-1001.0.46.4)]
```

##### CONFIGURATION
<!--- Paste verbatim output from "ansible-config dump --only-changed" between quotes -->
```
HOST_KEY_CHECKING(/Users/oha/.ansible.cfg) = False
```

##### OS / ENVIRONMENT
<!--- Provide all relevant information below, e.g. target OS versions, network device firmware, etc. -->
Mac OS 10.14

##### STEPS TO REPRODUCE
<!--- Describe exactly how to reproduce the problem, using a minimal test-case -->
---
```
- hosts: all
  connection: local
  gather_facts: True

  tasks:
    
  - debug:
      msg: "{{ config.instanceuuid }}"
  
  - debug:
      msg: "{{ config.name }}"

  - name: Set virtual machine custom attributes using name
    vmware_guest_custom_attributes:
      validate_certs: False
      state: present
      name: "{{ config.name }}"
      attributes:
        - name: CreatedBy
          value: myuser
        - name: CreatedOn
          value: "{{ ansible_date_time.date }}"
    
  - name: Set virtual machine custom attributes using uuid
    vmware_guest_custom_attributes:
      validate_certs: False
      state: present
      use_instance_uuid: True
      uuid: "{{ config.instanceuuid }}"
      attributes:
        - name: CreatedBy
          value: myuser
        - name: CreatedOn
          value: "{{ ansible_date_time.date }}"
```
<!--- HINT: You can paste gist.github.com links for larger files -->

##### EXPECTED RESULTS
<!--- Describe what you expected to happen when running the steps above -->
That all tasks are executed with state OK

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

TASK [debug] ******************************************************************************************************************************************************************************************************************************************************************
ok: [virtualmachine09_4227e011-59a6-7730-4191-3192cce23b35] => {
    "msg": "5027c056-98e0-7923-d25b-e37b628a8960"
}

TASK [debug] ******************************************************************************************************************************************************************************************************************************************************************
ok: [virtualmachine09_4227e011-59a6-7730-4191-3192cce23b35] => {
    "msg": "virtualmachine09"
}

TASK [Set virtual machine custom attributes using name] ***********************************************************************************************************************************************************************************************************************
changed: [virtualmachine09_4227e011-59a6-7730-4191-3192cce23b35]

TASK [Set virtual machine custom attributes using uuid] ***********************************************************************************************************************************************************************************************************************
fatal: [virtualmachine09_4227e011-59a6-7730-4191-3192cce23b35]: FAILED! => {"changed": false, "msg": "missing required arguments: name"}

PLAY RECAP ********************************************************************************************************************************************************************************************************************************************************************
virtualmachine09_4227e011-59a6-7730-4191-3192cce23b35 : ok=4    changed=1    unreachable=0    failed=1    skipped=0    rescued=0    ignored=0   

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

```

def __init__(self, module):
        super(VmAttributeManager, self).__init__(module)
    def set_custom_field(self, vm, user_fields):
        result_fields = dict()
        change_list = list()
        changed = False
        for field in user_fields:
            field_key = self.check_exists(field['name'])
            found = False
            field_value = field.get('value', '')
            for k, v in [(x.name, v.value) for x in self.custom_field_mgr for v in vm.customValue if x.key == v.key]:
                if k == field['name']:
                    found = True
                    if v != field_value:
                        if not self.module.check_mode:
                            self.content.customFieldsManager.SetField(entity=vm, key=field_key.key, value=field_value)
                            result_fields[k] = field_value
                        change_list.append(True)
            if not found and field_value != "":
                if not field_key and not self.module.check_mode:
                    field_key = self.content.customFieldsManager.AddFieldDefinition(name=field['name'], moType=vim.VirtualMachine)
                change_list.append(True)
                if not self.module.check_mode:
                    self.content.customFieldsManager.SetField(entity=vm, key=field_key.key, value=field_value)
                result_fields[field['name']] = field_value
        if any(change_list):
            changed = True
        return {'changed': changed, 'failed': False, 'custom_attributes': result_fields}
    def check_exists(self, field):