# Buggy code
def reset(module, conn, name, values):
    """Reset ElastiCache parameter group if the current information is different from the new information."""
    # used to compare with the reset parameters' dict to see if there have been changes
    old_parameters_dict = make_current_modifiable_param_dict(module, conn, name)

    format_parameters = []

    # determine whether to reset all or specific parameters
    if values:
        all_parameters = False
        format_parameters = []
        for key in values:
            value = text_type(values[key])
            format_parameters.append({"ParameterName": key, "ParameterValue": value})
    else:
        all_parameters = True

    try:
        response = conn.reset_cache_parameter_group(
            CacheParameterGroupName=name,
            ParameterNameValues=format_parameters,
            ResetAllParameters=all_parameters,
        )
    except botocore.exceptions.ClientError as e:
        module.fail_json(
            msg="Unable to reset cache parameter group.",
            exception=traceback.format_exc(),
            **camel_dict_to_snake_dict(e.response),
        )

    # determine changed
    new_parameters_dict = make_current_modifiable_param_dict(module, conn, name)
    changed = check_changed_parameter_values(
        values, old_parameters_dict, new_parameters_dict
    )

    return response, changed


# Traceback (KeyError)
The full traceback is:
Traceback (most recent call last):
File "/tmp/ansible_wAJvSx/ansible_module_elasticache_parameter_group.py", line 330, in <module>
main()
File "/tmp/ansible_wAJvSx/ansible_module_elasticache_parameter_group.py", line 305, in main
modifiable_params = make_current_modifiable_param_dict(module, connection, parameter_group_name)
File "/tmp/ansible_wAJvSx/ansible_module_elasticache_parameter_group.py", line 156, in make_current_modifiable_param_dict
modifiable_params[param["ParameterName"]] = [param["AllowedValues"], param["DataType"], param["ParameterValue"]]
KeyError: 'AllowedValues'

fatal: [localhost]: FAILED! => {
"changed": false,
"failed": true,
"module_stderr": "Traceback (most recent call last):\n  File \"/tmp/ansible_wAJvSx/ansible_module_elasticache_parameter_group.py\", line 330, in <module>\n    main()\n  File \"/tmp/ansible_wAJvSx/ansible_module_elasticache_parameter_group.py\", line 305, in main\n    modifiable_params = make_current_modifiable_param_dict(module, connection, parameter_group_name)\n  File \"/tmp/ansible_wAJvSx/ansible_module_elasticache_parameter_group.py\", line 156, in make_current_modifiable_param_dict\n    modifiable_params[param[\"ParameterName\"]] = [param[\"AllowedValues\"], param[\"DataType\"], param[\"ParameterValue\"]]\nKeyError: 'AllowedValues'\n",
"module_stdout": "",
"msg": "MODULE FAILURE",
"rc": 0
}

# Fixed code
def reset(module, conn, name, values):
    """Reset ElastiCache parameter group if the current information is different from the new information."""
    # used to compare with the reset parameters' dict to see if there have been changes
    old_parameters_dict = make_current_modifiable_param_dict(module, conn, name)

    format_parameters = []

    # determine whether to reset all or specific parameters
    if values:
        all_parameters = False
        format_parameters = []
        for key in values:
            value = to_text(values[key])
            format_parameters.append({"ParameterName": key, "ParameterValue": value})
    else:
        all_parameters = True

    try:
        response = conn.reset_cache_parameter_group(
            CacheParameterGroupName=name,
            ParameterNameValues=format_parameters,
            ResetAllParameters=all_parameters,
        )
    except botocore.exceptions.ClientError as e:
        module.fail_json(
            msg="Unable to reset cache parameter group.",
            exception=traceback.format_exc(),
            **camel_dict_to_snake_dict(e.response),
        )

    # determine changed
    new_parameters_dict = make_current_modifiable_param_dict(module, conn, name)
    changed = check_changed_parameter_values(
        values, old_parameters_dict, new_parameters_dict
    )

    return response, changed