# Flatten

Flatten a nested map or array into a flat map.

### Config
The following configuration defines the transform parameters. Each field's specifications, such as type, requirements, default values, and descriptions, are detailed below.
```json
{
  "operation": {
    "type": "string",
    "item_type": "",
    "required": true,
    "default": "drop_record_where_value_eq",
    "enum": null,
    "immutable": true,
    "description": ""
  },
  "arguments": {
    "key": {
      "type": "string",
      "item_type": "",
      "required": true,
      "default": null,
      "enum": null,
      "immutable": false,
      "description": "The key which values should be checked"
    },
    "value": {
      "type": "any",
      "item_type": "",
      "required": true,
      "default": null,
      "enum": null,
      "immutable": false,
      "description": "The value to compare with the record's value"
    }
  }
}
```
### Example

This example shows how to use the DropRecordWhereValueEq transformation to remove a record where the value of a specified key equals a given value.

```json
{
	"operation": "drop_record_where_value_eq",
	"arguments": {
		"key": "field_to_check",
		"value": "value_to_check"
	}
}
```

Given the input record:

```json
{
	"field_to_check": "value_to_check",
	"another_field": "another_value"
}
```

The record will be dropped and not included in the output.

If the value does not match:

Given the input record:

```json
{
	"field_to_check": "different_value",
	"another_field": "another_value"
}
```

The output record will be unchanged:

```json
{
	"field_to_check": "different_value",
	"another_field": "another_value"
}
```