# Mutate the value where Key Equal and Value Equal

Mutate a value where value equals the specified value and key equals the specified key.

## Example

This example shows how to use the MutateValueWhereKeyEqAndValueEq transformation to mutate a value where the key equals a specified key and the value equals a specified value.

```json
{
	"operation": "mutate_value_where_key_eq_and_value_eq",
	"arguments": {
		"key": "field1",
		"value": "old_value",
		"value_to_set": "new_value"
	}
}
```

Given the input record:

```json
{
	"field1": "old_value",
	"another_field": "another_value"
}
```

The output record will be:

```json
{
	"field1": "new_value",
	"another_field": "another_value"
}
```

If the key or value does not match:

Given the input record:

```json
{
	"field1": "different_value",
	"another_field": "another_value"
}
```

The output record will be unchanged:

```json
{
	"field1": "different_value",
	"another_field": "another_value"
}
```