public Snapshot assertThat(String value) {
    Checks.notNull(value, () -> "value is null");
    return new Snapshot(value);
  }
Specifies the {@code actual} value.
<p>
Note: The value is normalized by the normalizer function, defaults to line ending normalization.

@param value the actual value for assertions
spock-core/src/main/java/spock/lang/Snapshotter.java