assertThat(builder["e"]).isNull()
  }

  @Test fun builderSetOperator() {
    val builder = Headers.Builder()
    builder["a"] = "b"
    builder["c"] = "d"
    builder["e"] = Date(0L)
    builder["g"] = Instant.EPOCH
    assertThat(builder["a"]).isEqualTo("b")
    assertThat(builder["c"]).isEqualTo("d")
    assertThat(builder["e"]).isEqualTo("Thu, 01 Jan 1970 00:00:00 GMT")

	}
  ]
}
```

#### Common information available in all requests

- `aws:CurrentTime` - This can be used for conditions that check the date and time.
- `aws:EpochTime` - This is the date in epoch or Unix time, for use with date/time conditions.
- `aws:PrincipalType` - This value indicates whether the principal is an account (Root credential), user (MinIO user), or assumed role (STS)